IBF welterweight titleholder Devon Alexander had his way with tough but overmatched late-substitute Lee Purdy en route to a technical stoppage after the seventh round in the co-featured bout to the Lamont Peterson-Lucas Matthysse fight on Saturday in Atlantic City, N.J.

Alexander’s title was not on the line as Purdy, who stepped in for injured mandatory challenger Kell Brook three weeks ago, failed to make the welterweight limit of 147 pounds at Friday’s weigh-in.

However, Alexander (25-1, 13 knockouts) still performed like a champion, outclassing the 25-year-old British slugger with an impressive high-volume combination-punching attack from the opening round until Pudy’s trainer Tony Sims kept the underdog in his corner after the seventh round.

Alexander hurt his left hand in the opening round but the southpaw speedster still teed off with right hooks to the body and head and with right uppercuts. Purdy (20-4-1, 13 KOs) covered up while standing in front of Alexander, occasionally throwing a stiff right, but he was painfully slow and plodding.

“I hit him on top of the head and hurt my left hand but I had to put that out of my mind and win,” Alexander told Showtime commentator Jim Gray after the fight. “I wanted to impress tonight. My left hand was on point in camp. It would have been sharp tonight, but I had to use my right hand more.

“There’s going to be a lot of critics who say Lee Purdy wasn’t all that, but he was a tough fighter, who beat a lot of good fighters in the UK.”