Nonito Donaire moves on in WBSS after injured Ryan Burnett quits before Round 5

Donaire wins by TKO to win WBA title (0:50)

The ref stops the fight after the fourth round as Nonito Donaire wins the WBA bantamweight title from Ryan Burnett. (0:50)

It was a triumphant occasion for Nonito Donaire, who captured the WBA bantamweight title and moved on to the semifinals of the World Boxing Super Series by defeating Ryan Burnett by fifth-round TKO at the SSE Hydro in Glasgow, Scotland, on Saturday.

But the fight's conclusion was certainly anticlimactic as Burnett (19-1, 9 KOs), who came in as the defending champion, was suddenly stricken with what looked to be a lower-back injury after throwing a right hand in the fourth round. Burnett took a knee in the immediate aftermath, when he took the mandatory eight count from referee Howard Foster.

Burnett survived the round and was able to make it back to his corner. The Associated Press reported that Burnett needed oxygen after being carried out of the ring with an apparent hip injury.

"At that moment I was already getting my groove on," Donaire said by phone after the victory. "I felt my speed coming in and I was feinting and I was moving really, really well. So at the moment, I really didn't know what was going on with it. All I know was he was grimacing and from that point on it was, 'Well, OK, we can't do nothing about that.' But I was kind of confused with what was going on."

What was a solid back-and-forth encounter with both fighters having their moments in the early rounds was suddenly waved off, with Burnett unable to go on. The official result was a TKO at 1 second into Round 5.

While it might have been a bittersweet victory for the 35-year-old "Filipino Flash," it's one that he will still savor as he added to his vast collection of world titles ranging from flyweight to junior featherweight.

"No, it's a victory, I just felt bad for him," Nonaire said, "but we worked really hard for this fight. We're celebrating this victory, but again, I feel bad for him. That's pretty much it."

Despite not having performed at 118 pounds since 2011, a span of 15 fights, and having to come down two full weight classes from his previous bout (an April 21 loss to Carl Frampton as a featherweight), Donaire still showed his trademark speed and quickness against the 26-year-old Burnett.

Said Donaire: "Going into the early rounds I was feeling a little bit sluggish because I'm so accustomed to fighting bigger guys. But when [trainer] Kenny [Adams] and I started to connect, that's when I really started to box really well and started to use my speed.

''Ultimately, I felt really good and learned a lot and saw a lot of what I'm capable of in the division."

Donaire (39-5, 25 KOs) will meet Zolani Tete (28-3, 21 KOs), the defending WBO bantamweight titleholder. Tete outpointed Mikhail Aloyan in Russia last month in a WBSS quarterfinal.

"I've seen him before and I know what he's capable of," Donaire said. "He's a lengthy guy, a southpaw, and we're very cordial when we see each other. But aside from that I don't really [know much], but I'm very excited for the fight."

The card culminated with undefeated junior welterweights Josh Taylor and Ryan Martin in another series quarterfinal. Taylor (14-0, 12 KOs) dominated Martin (22-1, 12 KOs) over seven one-sided rounds. Taylor will fight Ivan Baranchyk (19-0, 12 KOs) in the semifinals.