MACAU (AP) -- Russia's Evgeny Gradovich retained the IBF featherweight title when Australia's Billy Dib quit in the ninth round Sunday at The Venetian casino in Macau.
In a rematch of their March bout, Gradovich put Dib down in the sixth round and staggered him with a left hook in the eighth. Further punishment in the ninth prompted Dib's corner to ask the referee to stop the fight on the undercard of the bout between Brandon Rios and Manny Pacquiao.
Mexican heavyweight Andy Ruiz Jr. extended his unbeaten record when American opponent Tor Hamer quit after three rounds despite leading on two of the three judges' scorecards. Ruiz retained his WBO intercontinental heavyweight belt and added the NABF title.
Zou Shiming, China's two-time Olympic gold medalist, improved his professional record to 3-0-0 with a unanimous points decision in his six-round flyweight bout against Mexico's Juan Toscano.
After an even opening couple of rounds, Zou poured on the pressure in the third, opening a cut under the Mexican's right eye, and sustained his dominance from then on to claim an impressive victory.
Highly touted lightweight Felix Verdejo of Puerto Rico improved to 8-0-0 with a unanimous points decision over Petchsamuthr Duanaaymukdahan, exhibiting too much hand speed and movement for the resilient Thai.
The other bouts included Filipino lightweight Harmonito Dela Torre knocking out Indonesia's Jason Butar Butar in the third round; China's Ik Yang taking a split decision over Indonesia's Hero Tito; local Macao fighter Kuok Kun Ng taking a unanimous decision over China's Zeng YouJie; Hong Kong's Rex Tso stopping Thailand's Susu Sithjadaeng in the first round; and Filipino Dan Nazareno Jr. beating Liam Vaughan when the Englishman's corner stopped the fight in the second round.