By Keith Idec

Claressa Shields’ most difficult professional fight also drew her highest ratings.

According to ratings released Tuesday by Nielsen Media Research, Shields’ victory over Hanna Gabriels drew a peak audience of 410,000 on Friday night. Their 10-round, 160-pound championship match was watched by an average audience of 376,000.

That made Shields-Gabriels the most-watched of the four Shields fights Showtime has televised. Shields-Gabriels also produced higher ratings than Showtime’s live airing of the Anthony Joshua-Joseph Parker heavyweight title unification fight March 31 from Cardiff, Wales.

Joshua’s win against Parker, which aired late in the afternoon on the East Coast of the United States, was watched by a peak audience of 379,000 and averaged 346,000 viewers. Showtime’s same-day replay of Joshua-Parker, which aired in prime time on the East Coast, attracted higher ratings than the live broadcast (peak: 483,000; average: 430,000).

The undefeated Shields also produced a significant spike in ratings from the two-time Olympic gold medalist’s first three appearances on Showtime.

Her previous appearance, a 10-round domination of 41-year-old Tori Nelson, drew an average audience of 320,000 on January 12 from Verona, New York. Shields’ Showtime debut, a fourth-round stoppage of Szilvia Szabados in March 2017 at MGM Grand in Detroit, averaged 241,000 viewers.

Shields survived a first-round knockdown against Gabriels to win a unanimous decision at Masonic Temple in Detroit. Judges Michael Ancona (98-91), Jeremy Hayes (97-92) and Pasquale Procopio (97-92) all scored the fight for Shields.

The 23-year-old Shields (6-0, 2 KOs), of Flint, Michigan, became a two-division world champion Friday night by adding the then-vacant IBF and WBA middleweight championships to her resume.

She moved down from 168 pounds to battle Costa Rica’s Gabriels (18-1-2, 11 KOs), who moved up from 154 pounds for their middleweight title fight. Shields previously won the IBF and WBC super middleweight titles.

Shields is expected to meet Germany’s Christina Hammer next in a middleweight championship unification fight.

Hammer (23-0, 10 KOs, 1 NC) easily out-boxed Nelson (17-2-3, 2 KOs) to win a unanimous decision in the 10-round bout Showtime televised immediately before Shields-Gabriels. The 27-year-old Hammer holds the WBC and WBO middleweight titles.

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