Mario Barrios retained the WBC welterweight championship after a majority draw against Manny Pacquiao on his comeback to the ring.
The 46-year-old Pacquiao was ahead going into the 10th round in Las Vegas, but all three judges scored the final three rounds for his younger opponent.
Two judges scored the draw, but the third gave Barrios a 115-113 victory.
Pacquiao entered the fight aiming to break his own record as the oldest welterweight champion, which he set in 2019 at age 40.
Barrios entered as the betting favourite but failed to deliver a convincing victory.
"I thought I won the fight," Pacquiao said in the aftermath of the loss.
"A close fight. My opponent was very tough. A wonderful fighter."
In the night's co-main event, Sebastian Fundora retained his WBC super welterweight title after Australian Tim Tszyu did not come out for the eighth round of their rematch.
