By Keith Idec

Al Haymon’s mission to expose emerging star Errol Spence Jr. to a bigger audience was an indisputable success Sunday.

Lou DiBella, the promoter of Haymon’s Premier Boxing Champions card Sunday in Brooklyn, confirmed to the Los Angeles Times on Monday night that the Spence-Leonard Bundu fight drew a 4.6 overnight rating. That means roughly six million viewers watched Spence’s sixth-round knockout of Bundu in their IBF welterweight elimination match at Ford Amphitheater at Coney Island.

NBC is expected to announce the official final rating sometime Tuesday, but the initial figures indicate the Spence-Bundu bout drew the largest rating of any PBC broadcast on network television since its inaugural show in March 2015.

Sunday’s output roughly tripled the viewership of Spence’s previous appearance on NBC, a fifth-round knockout of former WBO super lightweight champ Chris Algieri (21-3, 8 KOs) on April 16 at Brooklyn’s Barclays Center. That fight headlined a doubleheader that aired live on a Saturday night.

The Spence-Bundu bout was watched by millions more people in large part because it immediately followed the Olympic gold-medal men’s basketball game between the United States and Serbia. Team USA began blowing out Serbia in the first half, and although the game wasn’t remotely competitive during the second half, the strong lead-in clearly expanded the Spence-Bundu audience.

NBA superstars Carmelo Anthony and Kevin Durant were among the American players who were proudly displaying their gold medals during a post-game ceremony that ended less than three minutes before NBC’s broadcast of the Spence-Bundu battle began.

The Los Angeles Times also reported that the Spence-Bundu fight retained approximately 75 percent of its initial viewership.

The 41-year-old Bundu (33-2-2, 12 KOs) remained reasonably competitive for the first three rounds, but Spence started breaking him down and hurt him during the sixth round. A left-right combination by Spence knocked Bundu unconscious briefly and their scheduled 12-rounder was halted at 2:06 of the sixth.

The 26-year-old Spence, a 2012 Olympian from DeSoto, Texas, improved to 21-0 and recorded his 18th knockout. He is expected to fight for the IBF 147-pound championship in his next fight, presumably against someone other than current IBF title-holder Kell Brook (36-0, 25 KOs).

England’s Brook is expected to relinquish the IBF welterweight title after facing IBF/WBA/WBO middleweight champ Gennady Golovkin (35-0, 32 KOs) on Sept. 10 in London (HBO).

Keith Idec covers boxing for The Record and Herald News, of Woodland Park, N.J., and BoxingScene.com. He can be reached on Twitter @Idecboxing.