Masters made a claim that his version of the full nelson hold he dubbed the Master Lock was unbreakable, and began a series of contests he would call "Master Lock Challenges". Originally he would call out plants from the crowd, placing a $1,000 prize of his own money to be paid to anyone who could break free from the Master Lock. At Backlash, he defeated Melissa Coates in a Master Lock Challenge. He engaged in feuds with lower-card wrestlers, Val Venis and Sgt. Slaughter, who both failed to break the Master Lock. Using villainous tactics, he often attacked the wrestlers beforehand and frequently cheated (for example using a low-blow to escape Sgt. Slaughter's cobra clutch). Masters increased the offered reward each week up to $20,000 and sometimes threw in a bonus. After defeating the 400-pound Rosey on July 18, Masters defiantly stated "it doesn't matter how big they are!", prompting The Big Show to accept a "Master Lock Challenge". In accordance with his villainous persona, Masters fled, refusing a match with the Big Show.
In late August, Masters entered a feud with Shawn Michaels, leading to a tag match between himself and Carlito against Ric Flair and Michaels. During the match, Masters defeated Ric Flair by submission. Masters regularly teamed with Carlito, albeit in a rigid business relationship. Michaels competed in a "Master Lock Challenge" on September 5. Masters, upset at the vigorous resistance of Michaels, released the hold and beat him with a steel chair before re-applying the hold. The "Challenge", which had not decided a clear victor between the two, led to a match at Unforgiven which Michaels won.
Masters, alongside fellow Raw wrestler, Edge, was one of several wrestlers to "invade" SmackDown! in preparation for the match between the SmackDown! and Raw brands at Survivor Series. The two ambushed Rey Mysterio, leading to a tag match at Taboo Tuesday against Mysterio and Matt Hardy. Edge could not participate, so Masters teamed with Edge's replacement, Gene Snitsky. Masters and Snitsky lost when Mysterio pinned Masters. At Survivor Series, Masters competed in a five-on-five Survivor Series match between SmackDown! and Raw wrestlers. During the match their appeared to be a near-break in the Master Lock by Bobby Lashley, who "powered out" of the hold. As the hold was never completely locked in, however, the "Master Lock" had not been officially broken.
Masters had his first WWE Championship match on the November 28 edition of Raw. It was a Triple Threat Submission Match with Kurt Angle and John Cena. Prior to the match, Masters made headlines after attacking then-champion Cena from behind following one of Cena's matches. Masters applied the Master Lock hold, and became the first wrestler to bring Cena to unconsciousness, as Cena was unable to break the hold. During their match, Masters was struck with a chair shot from Cena, who ultimately retained the title, forcing Masters to tap out to Cena's STF-U.
Masters portrayed the role of a bailiff during the mock trial for then General Manager Eric Bischoff on the December 5 edition of RAW, with WWE Chairman Vince McMahon as judge. Upon being called to the stand to testify for Bischoff's defense, he was asked to give his name, which he did saying his name was Chris Masters. He was immediately accused of perjury and disqualified as a witness, as McMahon broke kayfabe and stated that Masters' real name was Chris Mordetzky.
On December 12, Chris Masters defeated Viscera on an episode of Raw to gain a spot in the Elimination Chamber match for John Cena's WWE Championship at New Year's Revolution. Viscera was shown to be too big to cinch on the Master Lock until being grounded. On the December 26 edition of Raw, Masters faced Chavo Guerrero, in a Beat the Clock match to determine who would be the final entrant to be released from his pod in the Elimination Chamber. Masters had to defeat Guerrero in 5 minutes and 56 seconds, which was the time set by Michaels (when he defeated Snitsky in the opening match of the show). Guerrero managed to survive the Master Lock long enough so that Masters was unable to beat the clock. At New Year's Revolution, Masters was eliminated from the Elimination Chamber match when Carlito double-crossed him by delivering a low blow while he had Cena in the Master Lock and then used a roll-up for the pin. On January 9, after some heated words with Carlito, both men had a tag match against two men who were also having difficulties, Kurt Angle and Shawn Michaels. During the match, Michaels walked backstage, leaving Angle to fend for himself. Masters saw the opportunity and applied the Master Lock to Angle, thus gaining the victory. On January 16, Masters challenged Cena to take part in a Master Lock Challenge. Cena accepted the challenge and displayed signs that he might in fact break out of the hold, until Edge attacked Cena with his title belt and ended the challenge.
At the Royal Rumble, Masters again worked together with Carlito, but Carlito again double-crossed him and eliminated him from the match. On the February 6 edition of Raw both men were entered into a Road to WrestleMania Tournament, to determine the number one contender for a WWE Championship match at WrestleMania 22. In Masters' first round match up he would use the ropes for support in a victory against Kane, and secure himself a second round match up against the winner of a later match between Carlito and Rob Van Dam. Van Dam won that match. The next week on Raw, Van Dam was able to beat Masters and advance to the tournament final. After this, Masters continued to feud with one half of the World Tag Team Champions, Big Show, while Masters' on and off teammate Carlito would feud with Kane. On the March 6 edition of Raw, it was announced that Masters and Carlito would get a tag team title match at WrestleMania 22. At WrestleMania 22, the pair lost the match to Big Show and Kane. The pair argued amongst themselves after the match. During the next Raw, Masters began to feud with Carlito after Carlito attacked him from behind. This led to a match between the two men at Backlash which Carlito won.
After this, Masters pursued the WWE Intercontinental Championship but would leave for several months to go to drug rehab due to an addiction of painkillers. Before leaving, Masters was on the May 22 edition of Raw, losing a match to John Cena by submission to the STF-U. He returned to the ring during an OVW TV taping on August 6. He had lost much of his muscle mass, appearing much slimmer, although he still had some definition in his arms and abdomen. On the August 28 edition of Raw, Masters made his return against Cena. Along with less muscle mass, he sported a goatee and mustache leading Jerry "The King" Lawler to refer to him as a "leaner and meaner" Chris Masters. This change of image was short-lived, however, as Masters shaved the goatee and regained some of his muscle mass. When Masters returned, he was put in lower-card matches including a short feud with Super Crazy, who had moved from SmackDown!, with Masters coming out on the losing end of their matches. The pair would also compete in a losing effort, along with four other Superstars, in a Six-Pack Challenge for the Intercontinental Championship. Masters gained his first victory since his re-debut, against Jerry Lawler on the November 6 edition of Raw in a match where Eric Bischoff, General Manager for the night, forced Lawler to be first handcuffed to the top rope. Masters continued the feud with Lawler for a few weeks with Lawler also losing a "Master Lock Challenge" before defeating Masters.
On the December 4 episode of Raw, Jonathan Coachman set up a "Master Lock Challenge" against John Cena for the WWE Championship. Masters appearing to have the challenge won released the hold for a short time, allowing Cena to reverse the hold into his own Master Lock, forcing Masters to submit, retaining his title, and making Cena the first to win the Master Lock Challenge. At the start of 2007, Masters would restart his feud with Carlito, which led to several matches between the two. The first was a one-on-one contest at New Year's Revolution won by Masters. In a rematch the next night on Raw, Carlito came out victorious. On the January 15 edition of Raw, Ron Simmons, with interference from Super Crazy, almost became the third superstar to "win" the Master Lock Challenge. An attempted "Master Lock Challenge" for The Great Khali on the February 26 edition of Raw did not occur when Masters was unable to apply the hold to Khali. The Master Lock was officially broken on the March 19 edition of Raw, by ECW World Champion Bobby Lashley.
On the May 7 edition of Raw, Masters challenged Santino Marella for the Intercontinental Championship. Masters was unable to defeat the newcomer, losing via a roll-up. On the May 14 edition of Raw, he lost yet again to Marella, but on the May 28 edition of Raw, he defeated Marella in the "Master Lock Challenge". On the June 4 edition of Raw, Masters was once again defeated by Marella with a roll-up.
On the June 11 edition of Raw, Masters was drafted from Raw to SmackDown! as part of the 2007 WWE Draft. While on SmackDown! he was used sporadically including a few Master Lock Challenges. He had entered into a feud with Chuck Palumbo competing in several matches and an attempted "Master Lock Challenge" that did not begin as Masters fled the ring after Palumbo realized Masters was trying to trick him. Following this, Masters was suspended for 30 days for failing a drug test. Masters returned to SmackDown! on the October 5 edition, applying the Master Lock to Palumbo. On November 2, 2007, it was reported that Masters had been suspended for 60 days for having violated WWE's Substance Abuse and Drug Policy a second time. He was released from his WWE contract, six days later, on November 8, 2007.
Mordetzky returned to World Wrestling Entertainment (WWE) on July 27, 2009 as "The Masterpiece" Chris Masters. He entered the ring with an unabridged titantron, displaying his signature poses. He faced Montel Vontavious Porter in a match that resulted in a double-countout after he applied the Master Lock submission to MVP outside the ring. After regaining his energy, Porter was fuming at his loss. Under referee restraint, he was headed to follow Masters. A feud continued between the two as Porter was able to score a pinfall victory over Masters on the August 10 edition of Monday Night Raw. On November 2nd, Mordetzky was in the Raw's Got Talent hosted by Ozzy Osbourne, Sharon Osbourne, and The Great Khali, in which he performed a "special art piece" for Crazy Train by flexing his pecks to the beat. He later turned babyface. by saving Hornswoggle from Chavo Guerrero, and putting him in the Masterlock. He has also begun a love angle with Eve Torres.