Jermell Charlo-Brian Castano was Showtime’s most-watched live boxing match since December 2019.

Nielsen Media Research released viewership figures Tuesday that indicated an average of 422,000 watched the highly competitive, thoroughly entertaining battle between Castano and Charlo on Saturday night from AT&T Center in San Antonio. Showtime’s audience peaked at 536,000 toward the end of a 154-pound title unification fight that resulted in a controversial split draw.

Nielsen’s numbers for Charlo-Castano include only viewers that watched live on Showtime’s linear channel because Nielsen doesn’t track streaming services. ViacomCBS, which owns Showtime and BoxingScene.com, doesn’t release figures for those that stream Showtime live.

The average and peak audiences for Charlo-Castano were the highest for a live boxing match on Showtime since Gervonta Davis’ 12th-round stoppage of Yuriorkis Gamboa nearly 19 months ago. Davis-Gamboa, a WBA lightweight title fight at State Farm Arena in Atlanta, drew an average audience of 577,000 and a peak audience of 604,000.

Before Saturday night, Jermall Charlo, Jermell’s twin brother, was primarily responsible for Showtime’s largest audience for live boxing since the COVID-19 pandemic began in March 2020. Jermall Charlo, the WBC middleweight champion, helped draw an average of audience of 333,000 and a peak audience of 379,000 for his 12-round, unanimous-decision defeat of Mexico’s Juan Macias Montiel on June 19 at Toyota Center in Houston.

Charlo-Castano, meanwhile, was a back-and-forth fight in which each champion had his moments.

Houston’s Charlo (34-1-1, 18 KOs) buzzed Castano (17-0-2, 12 KOs) in the second round, clearly hurt him twice during the 10th round and hurt him again in the 11th round. Castano caught Charlo with a left hook in the third round that buckled Charlo’s knees, though Charlo recovered quickly.

Charlo’s comeback in the championship rounds enabled him to secure a debatable draw on the scorecards.

New Jersey’s Steve Weisfeld scored their fight 114-113 for Castano because the veteran judge scored the 10th round 10-8 for Charlo. Nevada’s Tim Cheatham scored Castano-Charlo a draw, 114-114.

Puerto Rico’s Nelson Vazquez strangely scored nine of the 12 rounds for Charlo, 117-111, a wide distance even Charlo questioned.

Charlo retained his IBF, WBA and WBC championships. Castano kept his WBO belt.

Charlo, 31, and Castano, 31, discussed the need for a rematch during a post-fight press conference. There was not, however, an immediate rematch clause in their contracts and mandatory obligations with the four aforementioned sanctioning organizations likely will send them in different directions for their next fights.

Castano-Charlo headlined a tripleheader Saturday night.

An average audience of 249,000 watched Showtime’s co-feature, Rolando Romero’s seventh-round knockout of Anthony Yigit. Viewership for Romero-Yigit peaked at 256,000.

The hard-hitting Romero (14-0, 12 KOs), of North Las Vegas, Nevada, dropped Sweden’s Yigit (24-2-1, 8 KOs) once late in the fifth round and twice during the seventh round. Their scheduled 12-round fight was contested at the 140-pound limit because Yigit came in 5.2 pounds overweight Friday for what was supposed to be a 135-pound fight for Romero’s WBA interim lightweight title.

The opener of Showtime’s telecast, an action-packed bout between Amilcar Vidal and Immanuwel Aleem, drew an average audience of 202,000 and a peak audience of 220,000. Uruguay’s Vidal (13-0, 11 KOs) edged Aleem (18-3-2, 11 KOs), of Richmond, Virginia, by majority decision in their fan-friendly, 10-round super middleweight match.

Judges Ruben Carrion (97-93) and Glen Crocker (97-93) scored their fight for Vidal. Judge Anthony De Los Santos scored Vidal-Aleem a draw, 95-95.

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