By Keith Idec

A sizeable audience watched Eleider Alvarez upset Sergey Kovalev on Saturday night.

Ratings released Tuesday by Nielsen Media Research estimated a peak audience of 813,000 viewers saw Alvarez come back to knock out Kovalev in the seventh round of their HBO “World Championship Boxing” main event. The Kovalev-Alvarez fight for Kovalev’s WBO light heavyweight title drew an average audience of 731,000 from Hard Rock Hotel & Casino in Atlantic City.

The Kovalev-Alvarez ratings were significantly higher than for Kovalev’s previous appearance on HBO. That fight, in which Russia’s Kovalev stopped unknown former amateur teammate Igor Mikhalkin in the seventh round March 3, attracted a peak audience of 674,000 and an average audience of 599,000.

The two-bout broadcast headlined by Kovalev-Mikhalkin drew lower ratings in part because it aired at the same time as a Showtime telecast that featured a heavyweight title bout between WBC champ Deontay Wilder and Luis Ortiz. Wilder’s 10th-round knockout of Ortiz was watched by a peak audience of roughly 1.2 million and averaged approximately 1.1 million viewers.

In his prior appearance on HBO, Kovalev’s second-round stoppage of Vyacheslav Shabranskyy peaked at 900,000 viewers and averaged 869,000. Kovalev won back the WBO light heavyweight title he lost to Andre Ward by winning that November 25 bout in The Theater at Madison Square Garden.

Alvarez (24-0, 12 KOs) was by far the toughest of Kovalev’s three opponents following his technical-knockout defeat to Ward in their June 2017 rematch in Las Vegas. The 34-year-old Colombian was down on all three scorecards when his right hand landed to the side of Kovalev’s head and sent him to the canvas in the seventh round.

Kovalev got up, but Alvarez floored him two more times. Referee David Fields waved an end to their scheduled 12-round fight at 2:45 of the seventh round.

Before Kovalev suffered his second TKO defeat in his past four fights, HBO’s opener featured WBA light heavyweight champ Dmitry Bivol beating Isaac Chilemba by unanimous decision in their 12-round fight. Bivol’s victory over South Africa’s Chilemba (25-6-2, 10 KOs) was watched by a peak audience of 632,000 and an average of 583,000 viewers.

Kyrgyzstan’s Bivol (14-0, 11 KOs) had hoped to fight Kovalev (32-3-1, 28 KOs) in a 175-pound title unification fight December 8. He is willing to fight the Quebec-based Alvarez that night, but Alvarez’s contract calls for him to give Kovalev an immediate rematch.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.