Three surprising knockouts highlighted the televised portion of the Amir Khan-Marco Antonio Barrera undercard that was shown on the Integrated Sports pay-per-view broadcast in the U.S.

Ola Afolabi’s stunning ninth-round knockout of Enzo Maccarinelli to claim the WBO “interim” cruiserweight title was the biggest shock on the undercard that helped entertain the 20,000 fans who packed the M.E.N. Arena in Manchester, England Saturday night.

For years, Afolabi had a reputation as one of the most adept and difficult sparring partners in Southern California, but with one monster right hand the crafty cruiserweight made the transition from respected gym fighter to bona fide contender.

Afolabi, a late substitute and 20-to-1 betting underdog, troubled Maccarinelli early, and even hurt the Welshman with a cross to the ear at the end of the third round, but then had to weather a storm from the former titleholder in the middle rounds.

After having trouble hitting Afolabi, who has excellent head and upper-body movement, in the early rounds, Maccarinelli (29-3, 22 knockouts) got wise to his elusive opponent and concentrated on a sustained body attack in rounds four, five, six and seven.

In these rounds, Maccarinelli smothered Afolabi and outworked the spoiler in close, but his high workrate took its toll. By the eighth round, Marccarinelli had the look of a fatigued fighter. He still out-hustled Afolabi, but his punches lacked pop and he ate his share of shots coming in.

Midway through the ninth, Afolabi (14-1-3, 6 KOs) loaded up and launched a perfectly timed right hand as Maccarinelli wound up with one of his own. Afolabi, leaning in, landed his punch first and laid Maccarinelli out flat on his back.

The upset victory capped off an 11-month comeback for Afolabi, who sat out 2006 and 2007 because he couldn’t get fights. Last April, Afolabi shocked undefeated prospect Eric Fields with a 10th-round TKO to serve notice to the cruiserweight division. Saturday, in Manchester, England, Afolabi arrived.

Nicky Cook, a popular British 130-pound titleholder, suffered a similar fate at the hands of Puerto Rican slugger Ramon Martinez, who stopped the Essex fighter in the fourth round of what had been an evenly matched contest.

Cook (29-2, 16 KOs) started well, working behind his jab while landing shots to the body. In the second round, Cook landed a few uppercuts and may have scored a flash knockdown near the end of the round when he clipped Martinez with a hook. Martinez stumbled back and one of his gloves touched the canvas, however, referee Dave Parris did not break up the fighters or issue a count.

Cook was the aggressor in round three, but in the fourth Martinez (22-0-1, 13 KOs) landed a left uppercut that all but ended the fight. Cook collapsed on impact and barely beat the 10-count, but his legs were clearly not under him as he tried to exchange with Martinez. A chopping short hook dropped Cook again, and the brave fighter beat the count again but Parris had seen enough and waved the bout off.

Martinez picked up the WBO belt, joining Ivan Calderon, Miguel Cotto, Daniel Santos and Juan Manuel Lopez as titleholders from Puerto Rico.

In the opening bout of the pay-per-view broadcast Manchester’s entertaining Matthew Hall dropped the taller, faster and more experienced Bradley Price three times in the second round to earn a technical knockout and the commonwealth junior middleweight title.

Hall (22-0, 15 KOs) lived up to his nicknames “Little Tyson” and “Little Bull”, pressuring Pryce from the opening bell and landing compact, accurate power punches in close.

A right hand dropped Pryce (27-7, 17 KOs) one minute into the second round. Pryce got up with the smirk on his face, but Hall quickly wiped it off with a series of hard shots to the veteran’s arms, ribs and the upper part of his head. A hook dropped Pryce for the second time and hook-cross combination ended matters in the final seconds of the round.