In the opening rounds, Mack scored with right-hand leads and lefts, but he absorbed blows, too. Vazquez worked behind a good jab and landed a particularly hard right to Mack's head in Round 2. Mack landed solid hooks in the third and had Vazquez desperately ducking a barrage.
But this one would go the distance. Mack began slipping, blocking and countering Vazquez's punches. For the second half of the bout, he threw counter right hands and occasional two- and three-punch combinations - banging consecutive hard left hooks in the seventh - and Vazquez became a target.
"Every time you hit him with that double left hook, you hurt him," said trainer Naazim Richardson, who worked Mack's corner, to the fighter afterward.
Mack had not fought since losing in May 2006, in an embarrassing manner, on live TV. Halfway through Round 6 of that fight, opponent Alejandro Berrio kissed Mack on the top of the head before knocking him out. Mack was dejected and avoided the gym and his friends for a while before returning to training.
Since then, Berrio has gone on to win the International Boxing Federation title belt, and Mack would like nothing better than a chance for revenge.
What would make Mack's comeback complete? "Berrio," Mack said. "Berrio."
On the undercard, Michael Grant, the 6-foot-7 former heavyweight contender, stopped journeyman Billy Zumbrun in the fifth round, raising his record to 42-3 with 32 knockouts.
Zumbrun (21-9-1) is a Utah fighter who in 2005 was served up as an opponent when a fading Riddick Bowe was trying to extend his career.