SYDNEY – After submitting Michael Bisping with a one-arm guillotine choke in this past weekend’s UFC Fight Night 55 headliner, Luke Rockhold wasted little time calling out a former opponent.

In this case, Rockhold (13-2 MMA, 3-1 UFC) set his sights on a fellow ex-Strikeforce champion: Ronaldo Souza (21-3 MMA, 4-0 UFC).

“All respect to ‘Jacare,’ but I’ll be beat you again,” he said. “I’m the No. 1 contender, and I’ll prove it any time I have to.”

Following the event, Rockhold said Souza wasn’t the only potential next opponent.

“I want to knock out the top guys,” he said. “Him and (Lyoto) Machida are the top, so either one will suit me fine.”

With Machida (21-5 MMA, 13-5 UFC) already set to headline UFC Fight Night 58 against C.B Dollaway (15-5 MMA, 9-5 UFC) on Dec. 20, a Rockhold vs. Souza rematch is more likely.

The pair first met back under the Strikeforce banner in 2011. In a war of attrition, Rockhold’s takedown defense was enough to keep Souza from applying his renowned submission game, and he earned a unanimous decision victory (via 50-45, 48-47 and 48-47 scores) to capture the Strikeforce middleweight title.

“I don’t why he’s above me in the rankings,” Rockhold said. “That definitely upsets me, people pegging him as the No. 1 contender.”

Souza is currently ranked No. 4 in the USA TODAY Sports/MMAjunkie MMA middleweight rankings, and Rockhold is No. 6. (No. 1 and reigning champ Chris Weidman meets No. 3 Vitor Belfort at UFC 184 on Deb. 28.)

Rockhold, who stopped Bisping in the second round of their main event at Sydney’s Allphones Arena on Friday, said he has improved more than Souza since their first fight.

“I think I’ve grown more,” he said. “I believe I’m more dynamic than him. I beat him the first time, and I was young. I was very nervous going into that fight. I wasn’t very technical, and I’m a different man now.”

Since his loss to Rockhold, Souza has won six straight fights, most recently defeating Gegard Mousasi in dominating fashion with a third-round rear-naked choke in September.

For complete coverage of UFC Fight Night 55, check out the UFC Events section of the site.

(Pictured: Ronaldo Souza and Luke Rockhold)