Photos: Mikaela Mayer Dominates Helen Joseph Over Ten Rounds

Mikaela Mayer made history Tuesday evening, but more importantly, she earned the win. Mayer (13-0, 5 KOs) outboxed Helen Joseph (17-5-2, 10 KOs) over 10 rounds, earning a unanimous decision (100-90 2x and 99-91) at the MGM Grand "Bubble." Mayer-Joseph marked the first female main event in Top Rank on ESPN history. (photos by Mikey Williams)

Mayer had been out of the ring since October 26, as she and Joseph were scheduled to fight June 9. A positive COVID-19 test for Mayer delayed the fight, but she scraped off the ring rust and put forth a dominating performance over the two-time world title challenger.

Following the bout, Mayer received a word of encouragement, and a promise, from Bob Arum.

The "Cassius" Clay Collard train rolled through Las Vegas once again, as Collard knocked out Lorawnt-T Nelson in the second round of a scheduled six-round middleweight contest. Collard (8-2-3, 3 KOs) improved to 4-0 on the year, including three victories over previously undefeated fighters. He knocked down Nelson (5-4, 4 KOs) in the opening round and twice more in the second before referee Celestino Ruiz stopped the fight.

Ruben Cervera (12-2, 10 KOs) picked up his second straight win, topping Clay "3rd Degree" Burns (9-9-2, 4 KOs) by six-round unanimous decision in a lightweight bout. Cervera knocked down Burns with a left hook in the opening round and prevailed by scores of 59-54 2x and 58-56.

Middleweight Javier Martinez had a successful professional debut, shutting out Ryan "The Lion" Burrs (2-2) over four rounds by identical 40-36 scores. Martinez, from Milwaukee, inked a multi-year professional contract with Top Rank following a storied amateur career with USA Boxing.