Mikaela Mayer and Sandy Ryan will take the next act of their rivalry to boxing’s longtime fight capital.

The Ring has learned that the pair of top-rated welterweights are nearing a deal to meet again on March 29 show at Fontainebleau Las Vegas. Mayer will defend her WBO welterweight title atop a card that will air on an ESPN platform.

Top Rank has a hold on the venue, as well as one week later for an April 5 show at Palms Casino Resort. However, Mayer’s first title defense is budgeted for the March 29 event, according to multiple sources with intimate knowledge of the details surrounding her next fight.

The rematch will come six months after their fantastic Sept. 27 clash. Mayer (20-2, 5 KOs)—a Los Angeles native who now trains in Las Vegas—won via majority decision to dethrone England’s Ryan (7-2-1, 3 KOs) at Madison Square Garden’s Hulu Theater in New York City.

The grudge match came with its share of controversy in and out of the ring. The final decision was debatable, though more so the 97-93 card in favor of Mayer.

Of greater concern was the pre-fight trauma experienced by Ryan. The now former titlist was hit with a can of red paint as she exited her hotel on the way to Hulu Theater for fight night. The assault remains under investigation, though Ryan’s team have continued to suggest that Mayer was involved, indirectly or otherwise.

Mayer has repeatedly denied having any role in the incident in question and publicly condemned the attack.

The win over Ryan saw Mayer become a welterweight titlist on her second try. She began the year in a thriller with England’s Natasha Jonas (16-2-1, 9 KOs), who won their Jan. 20 title fight via split decision in her Liverpool hometown.

Jonas successfully defended her IBF belt and since added the WBC title in a dominant points win over Ivana Habazin (23-6, 7 KOs) on Dec. 14, also in Liverpool.

Next up for Jonas is a March 7 unification bout with The Ring/WBA champion Lauren Price. The timing of Mayer-Ryan II will put The Ring’s top four welterweights in the ring and every major divisional title at stake all in the span of less than a month.

Jonas, Mayer and Ryan are No. 1, No. 2 and No. 3, respectively, to Price’s championship throne. Both Jonas (No. 9) and Mayer (No. 10) are among The Ring top ten pound-for-pound fighters.

Ryan won the WBO welterweight title in an April 2023 unanimous decision over unbeaten Marie Pier Houle in Cardiff, Wales. The feat came in just her seventh pro fight, and after she’d already avenged her lone career defeat to Erica Farias at the time.

Two successful defenses followed for Ryan, though the first one denied her the right to become The Ring champion. Many considered the Derby native unlucky to have been forced to settle for a draw in her Sept. 2023 unification with then-Ring, WBA and WBC champ Jessica McCaskill in Orlando, Florida.

Six months prior to her defeat to Mayer, Ryan earned her career-best win. Ryan tore through then-two division titlist Terri Harper (14-1-2 at the time) inside of four rounds last March 23 in Sheffield, England. The win aged remarkably well; Harper dethroned WBO lightweight titlist Rhiannon Dixon in her very next fight.

Mayer—who represented the U.S. in the 2016 Rio Olympics—previously held the IBF and WBO junior lightweight titles. She made three successful WBO title defenses before a disputed split decision defeat to Alycia Baumgardner 15-1 (7 KOs) in their Oct. 2022 Ring, WBC, IBF and WBO 130-pound championship unification in London.

The controversial defeat to Baumgardner—The Ring and undisputed 130-pound champ and No. 9 pound-for-pound fighter—was Mayer’s last at 130. She has since fought once each at lightweight and junior welterweight before the move up to welterweight, where she now aims to become undisputed champion before year’s end.