Former Bellator heavyweight champion Alexander Volkov served notice to the rest of the division Saturday, knocking out Fabricio Werdum in the main event of UFC Fight Night 127.

The card took place live on UFC Fight Pass from The O2 Arena in London.

Volkov remained unbeaten inside the Octagon, scoring himself a fourth round finish over the ex-UFC heavyweight champion.

“I am waiting,” Volkov said. “I am here for (the title).”

The 29-year-old Russian is now 30-6 overall and on a six-fight win streak that includes victories over Werdum, Stefan Struve, Roy Nelson and Tim Johnson.

For Werdum, the loss snapped a string of back-to-back wins. The 40-year-old falls to 23-8-1.

In the co-main event, Jan Blachowicz gained a measure of revenge, scoring a decision over Jimi Manuwa. Back in 2015, Manuwa scored a decision over Blachowicz.