Cesar Mateo Tapia scored a superb fifth-round stoppage of Sydney-based Russian Sergei Vorobev at the Horden Pavilion in Sydney, Australia.

They met on the undercard of Keith Thurman-Brock Jarvis, with an excellent right hand ultimately causing the end of the fight.

Asked what might come next, Tapia said: “I’m not sure. The middleweights know who I am and where I’m at. It’s pretty cringy to call people out. They know where I’m at. If they want to fight, I’m here.”

Both boxers came out swinging, trying to set up big shots. Both were rangy and game, firing out hard jabs and attempting to catch one another with heavy punches behind their lefts.

Vorobev picked up a verbal warning for hitting behind the head in the fourth and Tapia was coming out of the exchanges with the upper hand. Then, in the fifth, Tapia made his advantage count, dropping Vorobev with a terrific overhand right.

Although Vorobev made it back to his feet, the referee waved it off. Vorobev tried to demonstrate he was okay to continue by performing some jumping push ups in the middle of the ring, but they counted for nothing. It was over after 1.26 of the fifth.

Incidentally, Tapia (pictured right) was in a war in October, when he battled to a draw with Endry Saavedra on the Bakhram Murtazaliev-Tim Tszyu undercard in Florida.

Tapia is 18-0-1 (11 KOs). Vorobev is now 20-3-2 (14 KOs).

Light-heavyweight contender Tonga Tongotongo, a thick-set former rugby league player, suffered the first loss of his career, when stopped after six rounds by the impressive Kirra Ruston.

At the end of the fifth, Ruston clocked Tongotongo with a heavy right hand but there was not much between them. However, it was a sign of things to come. Ruston worked his way on top in the sixth, pinning Tongotongo on the ropes and lashing him with another right. Ruston took one in reply, but he remained on top and his volume overwhelmed Tongotongo, who fell in a heap against the ropes.

Although Tongotongo made it back to his feet, where he was greeted by the bell to end the session, he was withdrawn between rounds, his left eye almost swollen shut, and saved for another day.

Tongotongo is now 9-1 (9 KOs), while Perth’s Ruston, the new Australia light-heavyweight champion – already booked to fight again on April 26 – improves to 5-0 (5 KOs).

There was also a unanimous decision victory for Linn Sandstrom after 10 two-minute rounds at super flyweight against Yoselin Fernandez, victory over six twos for junior lightweight Nadia Flalhi over Angel Rushton, over five rounds for Jacob Clenshaw, at welterweight against Kavana Vaotu’ua, and at the conclusion of four rounds at junior middleweight, for Jordan Martin over Sonny Knight.

Lightweight Charlie Kazzi, aged 19 and now 8-0 (4 KOs), stopped Nort Beauchamp, 19-9-1 (3 KOs), in the first of five rounds, and at welterweight Jason Fawcett, 9-2 (2 KOs), stopped 1-2 (1 KO) Kohei Hatanaka – a Japanese fighter who lives in Australia – in the second of six.