Brunk revealed in a shoot promo and in the documentary film Forever Hardcore that in fact it was not Paul Heyman that brought him into Extreme Championship Wrestling (ECW) but that he was at the right place at the right time. He was referred by a friend to Tod Gordon. According to the storyline, Sabu, who at that time often arrived to the ring by his handler 911, was an uncontrollable madman strapped to a gurney and with a Hannibal Lecter-style face mask while trying to break free (he claimed to hate this part of his gimmick as he was normally tired before he started his match). Sabu could only be released from his bonds to wrestle his matches. Sabu also quickly became synonymous with table-breaking at this time; if a table was not broken during the match, Sabu would break a table with his own body after the bell had sounded. Sometimes leading to 911 having to restrain Sabu during backstage interviews if a table was present.
One of the most notable aspects of Sabu's early career was his refusal to speak, a gimmick that he inherited from The Sheik (who never spoke English in public to protect kayfabe). In his early career, Sabu was billed as being from Saudi Arabia, or Bombay, India (in real life he is a second generation Lebanese American from Detroit). In ECW, however, he was clearly heard to speak in the ring on several occasions and it was fairly common knowledge that Brunk was an American citizen from birth. This led to a joke at kayfabe's expense when Sabu began to be billed as hailing from "Bombay, Michigan".
The most significant matches during the early part of Sabu's career in ECW were his three way dance for the ECW Championship at The Night the Line Was Crossed, against Terry Funk and Shane Douglas, which went to a 1 hour time limit draw and his tag team feud with The Public Enemy in which Sabu and his partner The Tazmaniac capture the ECW Tag Team Championship in a double tables match. Another notable event occurred when, after being scheduled for a 3-way dance for the ECW Tag Team title, Sabu no–showed the event to accept a booking in Japan, which led Paul Heyman to publicly and legitimately fire Sabu at the event. Sabu stated in the Forever Hardcore documentary that he had a career wrestling in Japan yet only wrestled once every so often for ECW; thus, he chose Japan over ECW.
Sabu made his WCW debut on September 11, 1995 on an edition of WCW Monday Nitro against Alex Wright. Sabu won the match, but the decision was reversed when after the match he put Wright through a table. Sabu continued to wrestle some of the cruiserweights in WCW in the early days of the division, including a match against Mr. J.L. at Halloween Havoc. Sabu came out victorious against J.L., and following the match Sabu's uncle Shiek hit J.L. in the face with his trademark fireball. His last match in WCW was against Disco Inferno, which Sabu won. Following his victory, he put Disco on a table on the outside and attempted to flip onto Disco but Disco moved. Sabu hit the table back first, but the table did not break. In response, Sabu began no selling the table spot and started throwing the table as well as the ring stairs.
He eventually returned to ECW the next year, and engaged in matches and feuds with the likes of Rob Van Dam, with whom he later teamed up with and won the ECW Tag Team Championship twice. In the meantime, former tag team partner Tazmaniac (who had shortened his name to "Taz") began to publicly challenge Sabu at every given opportunity, but got no response. After a year of call-outs and insults from Taz, Heyman revealed that he had asked Sabu, as a friend, to ignore Taz's challenge. This standoff culminated in a grudge match at ECW's first pay-per-view, Barely Legal, which Taz won. The two continued to feud on and off for the remainder of Taz's ECW career. Sabu mentioned in a shoot interview with RF Video that he didn't want to work with Taz for this match because he had already wrestled him before and wanted to work with other talent. He also mentioned that Taz calling him out for a year was not planned. Paul Heyman convinced Sabu to wrestle Taz at Barely Legal.
Sabu was later included in the WWF invasion angle, in which ECW wrestlers invaded WWF's Monday Night Raw program and held ECW-style matches and angles on the show. One memorable moment occurred at this show when Sabu appeared during Tazz's match with Mikey Whipwreck and prepared for an aerial move off the "R" in the "RAW" lettered entryway onto Team Tazz members, but instead accidentally fell off the "R". This was not planned which led to Sabu landing on top of Team Tazz members and becoming an inside joke between him and Tazz backstage. This invasion angle also led to a heel turn for Sabu in ECW as he teamed up with Rob Van Dam and their manager Bill Alfonso to promote the virtues of the WWF product over ECW's. Sabu feuded with ECW loyalists Tommy Dreamer and Sandman during this period.
One of Sabu's most infamous matches was the No-Rope Barbed-Wire match with Terry Funk at Born to be Wired, a match which was promoted as being "too extreme even for ECW" – and with good reason: both men bled profusely. In one of the most memorable moments in ECW history, Sabu attempted the "Air Sabu" corner splash on Terry Funk. Funk moved and Sabu ended up colliding violently into the wire which tore open his biceps. He then asked his manager Bill Alfonso for some tape and after Alfonso went to get some Sabu began to tape the gash up, which was about 10 inches long. Funk has stated that, to this day, he has never seen anything like what Sabu did that night. The match ended with both men so badly tangled up together in the barbed wire that it took several ring technicians armed with wire cutters to free them from the predicament (on the DVD Bloodsport – ECW's Most Violent Matches released by World Wrestling Entertainment, Paul Heyman said that the match was "so gruesome, I never ever dared to schedule another one like it", and that they never had another Barbed-Wire match in ECW because "no one could top that one – and in good conscience, I never want anyone to try") but Sabu said during his Shoot with RF Video that Heyman wanted to do another Bared-Wire match but would on ask for more money each time.
Brunk racked up an astounding catalogue of injuries during his ECW tenure, including broken ribs, a broken jaw, and breaking his neck twice. The first time he broke his neck was during his match with Chris Benoit at 1994 November to Remember event. Benoit threw Sabu, intending that he take a flapjack bump, but Brunk attempted to turn mid-air and take a back body drop bump instead. The other was during a match against Taz in December 1998, when Brunk took a Taz–Plex through a table and landed incorrectly. Brunk was able to recover from the neck injuries and return to wrestling, and he even wore a neck brace in his return match in the United States a month following the injury at Taz's hands; by Brunk's account, however, he started actively wrestling in Japan on a short tour a little over two weeks after that injury.
On April 24, 2006, Sabu's official website reported that he signed a one-year contract with World Wrestling Entertainment. At the One Night Stand pay-per-view, Sabu faced Rey Mysterio for the World Heavyweight Championship. At the end of the pay-per-view matchup, Mysterio found himself standing on a ringside table with Sabu flying at him. Sabu caught the champ in a front facelock and nailed him with a DDT which caused both men to crash through the table. At this point, the WWE medical staff rushed to the injured men and declared neither man could continue and ordered the match stopped, resulting in a No Contest in which Mysterio kept his title.
On the June 13 premiere of ECW on Sci Fi, Sabu won a 10 man Extreme Battle Royal with the stipulation that the winner face John Cena at Vengeance. Sabu further fueled the feud during the next week's Raw, when he interfered in a Cena match and performed a Triple Jump Leg Drop on him, diving onto Cena and putting him through the announcers' table. Cena defeated Sabu in their "Extreme Lumberjack match" at Vengeance. On July 2, Sabu, traveling with fellow ECW wrestler Rob Van Dam, was arrested and charged with possession of drug paraphernalia, and nine Vicodin tablets following a traffic stop in Hanging Rock, Ohio. Brunk was fined $1,000 based on the guidelines of WWE's Wellness Policy. Meanwhile, he defeated Stevie Richards in an Extreme Rules match at Saturday Night's Main Event.
Towards the end of July, Sabu began to talk on camera for himself - instead of using a go between - and demanded a shot at The Big Show's ECW World Championship which Paul Heyman refused to grant him in order to "protect" his champion. Instead he forced him into a match against the returning Kurt Angle to determine a number one contender. When that match was interrupted by the returning Rob Van Dam another match was signed, Angle versus Van Dam versus Sabu, for the number one contendership (Angle then became too injured to compete and was pulled from the match). Sabu beat Rob Van Dam in their ladder match to win a shot at Big Show at SummerSlam, a match which he ended up losing. After SummerSlam, he became a main eventer at ECW, with the majority of the matches being Extreme Rules. He also started to form tag teams with the likes of Rob Van Dam and The Sandman to face of Test, The Big Show, Paul Heyman and his ally Matt Striker.
At Survivor Series, Sabu teamed up with John Cena, Bobby Lashley, Rob Van Dam and Kane to face the team of The Big Show, Test, Montel Vontavious Porter, Finlay and Umaga. Sabu eliminated Test following a Tornado DDT, but he was later eliminated by Big Show via pinfall after receiving a chokeslam. In the end, Team Cena gained victory. At December to Dismember Sabu was originally to appear in the main event, an extreme elimination chamber match against The Big Show, Test, Rob Van Dam, CM Punk and Bobby Lashley, but was "taken out" and replaced by Hardcore Holly. The following episode on ECW, CM Punk and Rob Van Dam got on the mic before their match with Test and Hardcore Holly and dedicated the match to Sabu. When Punk and Van Dam won the match, Paul Heyman and his security team came out and had beaten down on the two. Sabu later made his return with a heavily wrapped arm to make the save. Sabu made his Royal Rumble debut in the 2007 Royal Rumble where he was eliminated by Kane after receiving a chokeslam over the top rope and through a table.
Sabu joined the ECW Originals along with Rob Van Dam, Tommy Dreamer and The Sandman. The ECW Originals began a feud with the New Breed (Elijah Burke, Kevin Thorn, Marcus Cor Von and Matt Striker). The two teams faced off in a match at WrestleMania 23 in which the ECW Originals won. The ECW after that, there was an ECW Extreme Rules match between the New Breed and the ECW Originals, which the New Breed won after Elijah Burke performed the Elijah Express on Sabu through a table. On May 16, 2007 Sabu was released from his WWE contract.