It’s not Buster Douglas knocking out Mike Tyson but it was a surprise nonetheless.

Showtime, which historically has come up short against HBO in the ratings war in part because of an approximately 30% smaller subscriber base, won Saturday night’s battle of the eyeballs in head-to-head boxing broadcasts.

Showtime’s excellent main event — Leo Santa Cruz’s majority decision win against Carl Frampton in a featherweight WBA title rematch — peaked at 643,000 viewers, based on ratings by Nielsen Media Research. That exceeded HBO’s main event, which also put on a first-rate scrap involving Miguel Berchelt stopping Francisco Vargas in the 11^th round for a WBC featherweight title that peaked at 549,000 viewers.

Santa Cruz-Frampton attracted an average viewership of 587,000 while Berchelt-Vargas did an average of 497,000. Both main events were broadcast live in the same 45-50-minute window in the 11pm ET spot. HBO’s entire broadcast peaked at 561,000 and that included a portion of Takashi Miura’s stunning 12th-round knockout of Miguel Roman in the 130-pound co-feature. HBO typically doesn’t make statements on viewership numbers and declined a request for comment on Tuesday.

“There were two great fights that had a lot of action for fans,” Showtime boxing boss Stephen Espinoza told RingTV.com on Tuesday, also referencing Mikey Garcia’s third-round knockout of Dejan Zlaticanin to claim a lightweight title in the co-feature. “It was certainly a great night of boxing for everyone who watched.”