IBF flyweight titleholder Amnat Ruenroeng (L) reacts to his unanimous-decision win over Zou Shiming on March 7, 2015, in Macau. Photo by Chris Farina/Top Rank.

IBF flyweight titleholder Amnat Ruenroeng handed Zou Shiming his first defeat on Saturday, winning a unanimous decision at the Venetian Resort in Macau, China on Saturday.

Ruenroeng (15-0, 5 knockouts) of Chonburi, Thailand, overcame a dubious knockdown call in Round 2 to win by scores of 116-111 on all three cards. The two-time Olympic gold medalist Shiming (6-1, 1 KO) was gracious in defeat, telling the media afterwards through a translator: “Tonight is regretful for me. But I’d like to congratulate my opponent.”

Still, the 33-year-old Zou asserted that his punches were more effective. “I don’t think my opponent was very aggressive.”

The win marks a career apex for the 35-year-old Ruenroeng, who was sentenced to 15 years in prison for robbery in 2006 but was released early in 2008 after winning the national amateur title.

Ruenroeng won the world title in January of 2014, defeating Rocky Fuentes to win the belt stripped from Moruti Mthalane. He then handed Kazuto Ioka his first defeat later that year before getting off the canvas to defeat mandatory challenger McWilliams Arroyo.

The main event put a damper on what was an otherwise successful night for Chinese boxing. As Zou’s career is reassessed in light of his first loss, the pressure now moves to the other leading boxers of the world’s most populous country to sustain the popularity of the sport in China.

Junior bantamweight Rex Tso (16-0, 9 KOs) of Hong Kong overcame a spirited challenge from Filipino boxer Michael Enriquez (10-3-1, 6 KOs), winning a unanimous decision by the scores of 95-94, 95-94 and 96-93.

Chinese junior welterweight Ik Yang (19-0, 14 KOs) kept his record pristine with a sixth-round technical knockout of Patomsuk Pathompothong (29-3-1, 18 KOs) in an IBF elimination bout. Yang and his Thai opponent traded blows from the opening bell, with the heavier-punching Yang scoring the stoppage at the 1:47 mark.

Macau favorite Kuok Kun Ng (7-0, 3 KOs) climbed off the canvas in Round 1 to stop Chingchai Kiatpracha (7-3, 3 KOs) at 2:35 of the third round. Ng dropped Kiapracha twice in the third to finish the bout.

Also that night, Glen Tapia (23-1, 15 KOs) of Passaic, New Jersey, scored his third straight victory since his lone loss in 2013, pounding out Australian Daniel Dawson (40-5-1, 26 KOs) at 1:42 of the third round.

Tapia, 25, held back his slugging instincts and boxed effectively before hurting Dawson and finishing him off shortly after.