New Delhi, Nov. 8 -- Johnny Walker was knocked down in the first round. By the third, he had knocked out one of the UFC's top heavyweights.

Walker defeated Waldo Cortes-Acosta by third-round knockout in the main event of UFC Vegas 124 on Saturday night at the Meta APEX in Las Vegas, according to CBS Sports. CBS Sports reported that Cortes-Acosta put Walker on the canvas in round one before Walker rallied. MMA News described the finish as a sudden head kick, though the reports reviewed differ in how they describe the closing sequence.

Essentially Sports reported that Walker took the fight on nine days' notice after the original main event fell through, and that he became the first fighter to knock out Cortes-Acosta. The Eastern Herald re...