Ryan Burnett retired through freak injury
Josh Taylor sizzles with stoppage
Darryll Williams in controversial points loss to Zach Parker
Ryan Burnett (19-1) was forced to surrender his WBA bantamweight title after sustaining a fight-ending back injury during his World Boxing Super Series quarter-final against Nonito Donaire (39-5).
The 26-year-old Belfast boxer, widely tipped as the favourite, had to take a knee in the fourth round as he seemingly overstretched or aggravated a back muscle and was forced to retire, leaving the ring on a stretcher. After the third round, Burnett could be heard telling trainer Adam Booth: "I cannot move it. I cannot throw a shot." He dropped to his knees in the next round after attempting to throw a punch, and pulled out of the fight at its conclusion.
Victory in Glasgow gave Donaire, 35, the WBA 'Super' and vacant WBC diamond belt.
The Filipino four-weight world champion will now face South African WBO title-holder Zolani Tete (28-3) in the semi-finals.
Josh Taylor (14-0) earned a super-lightweight title shot against IBF champion Ivan Baranchyk in the World Boxing Super Series semi-final after stopping unbeaten American Ryan Martin (22-1).
'The Tartan Tornado', 27, utterly dominated the bout and stopped 25-year-old American in the seventh segment.
Taylor is now unbeaten in 14 professional fights and inflicted Martin's first loss in 23 outings.
Should Taylor defeat Baranchyk, he will fight for the WBA title in the final.
Zach Parker (17-0) took the vacant British super-middleweight championship over Darryl Williams (17-1) via a very controversial split decision in a battle of the undefeated, most observers believing Williams had done more than enough to win.
Former world champion Viktor Postol (30-2) outpointed underdog Siar Ozgul (14-2) 99-91 in a non-title super-lightweight contest.
Paul Butler (27-2) defeated Yoan Boyeaux 99-91 on points.
Stephen Tiffney (10-1) beat Arturo Lopez (5-8-3) on points - 58-55 - in a super-featherweight six-rounder.
Michael McGurk moved up to 11-0 with a win over Miguel Aguilar (11-52-1).