When his training was completed in 1999, Lopez adopted the name "Mafia" and formed a tag team with another Doghouse graduate who he resembled, Monsta Mack.

After Mack injured his leg, he was unable to defend his half of the JAPW Tag Team Championship in a scheduled match on January 25, 2003, against the Dirty Rotten Scoundrelz.

Inspired by his victory, Lopez left the partnership with Mack, who he defeated in a match for USA Pro Wrestling on March 8.

Following a successful title defense against Slyk Wagner Brown, Lopez announced he was renaming himself "Dan Maff" and formed a stable with the Dirty Rotten Scoundrelz known as "La Familia".

Lopez's title reign came to an end on August 1, 2003, when he was defeated by Al Snow, a WWE employee brought into JAPW as an outside challenger.

Mack then formed a new version of La Familia with the Soundrelz and enlisted a number of heels to try to take the title away from Lopez.

Lopez's singles career in ROH began on May 31 at Do Or Die, where he defeated B. J. Whitmer with the assistance of Allison Danger, the valet of The Prophecy.

Whitmer joined The Prophecy on December 22 at Final Battle 2003, and confessed that he had been behind a career-ending attack on Lucy, the valet of CM Punk, earlier that year.

Lopez called Whitmer a "scumbag" but was admonished by Daniels, who claimed that the attack was part of his plan to destroy ROH.

Lopez and Whitmer began teaming together in 2004 after Daniels left ROH, and, along with Allison Danger, continued their feud with CM Punk and the Second City Saints.

They defeated the Saints in a match for the ROH Tag Team Championships on May 15, 2004, in Lexington, MA at Round Robin Challenge III, but lost the title to the Briscoe Brothers that same evening.

Lopez broke his retirement on October 8, 2005, unsuccessfully challenging El Chicano for the IWA Puerto Rico Heavyweight Championship in Levittown.

On March 19, 2010, Lopez defeated Rob Fury, El Shoes and Xavier at the ICW return show "Reborn" at the Elks Lodge in Queens, New York.

During the event, held in Rahway, New Jersey, Maff made his debut for the Japanese promotion, losing to Toru Yano via low blow in the first round of a tournament to determine the first IWGP Intercontinental Champion.

In June 2015, Maff became Pro Wrestling Syndicate Champion by defeating Mario Bokara and Fallah Bahh in a Tri Force Match.