Nonito Donaire becomes a world champion again after Ryan Burnett is forced to retire after freak hip injury

Four-weight world champion Nonito Donaire is a world champion again, as he won the WBA bantamweight title, and clinched his spot in the semifinals of the World Boxing Super Series with a fifth-round TKO over previously unbeaten Ryan Burnett at the SSE Hydro in Glasgow, Scotland, on Saturday.

But the fight was not decided by a punch. Burnett (19-1, 9 KO's), who came into the fight as the champion, appeared to injure his back after throwing a right hand in the fourth round. Burnett immediately took a knee and received a mandatory eight-count from referee Howard Foster.

Burnett was able to survive the round, but was unable to continue due to a freak hip injury. According to several reports, Burnett required oxygen after he was carried out of the ring on a stretcher.

Donaire (39-5, 25 KO's), 35, who was competing at 118 pounds for the first time since 2011, will meet Zolani Tete (28-3, 21 KO's), the WBO bantamweight titleholder in the WBSS semifinals. Tete defeated Mikhail Aloyan last month on points to advance.

There was also a battle of the undefeated between junior welterweights Josh Taylor and Ryan Martin in a 140-pound WBSS quarterfinal. Although a close matchup on paper, it was nowhere close in the ring. Taylor (14-0, 12 KO's) dominated Martin (22-1, 12 KO's), knocking him out inside seven rounds. Although the punch that ended the fight was behind the head, Martin was getting thoroughly outclassed. Taylor will face Ivan Baranchyk (19-0, 12 KO's) in the semifinals.