By Keith Idec

Claressa Shields defeated previously unbeaten opponents in each of her last two fights.

Shields still expects her 10-round, 160-pound championship match against Hanna Gabriels to be the toughest of her six professional fights when they meet Friday night in Detroit. The undefeated Shields has moved down from 168 pounds to 160 to battle Gabriels, who has moved up from 154 pounds to 160 for the opportunity to face Shields.

The 23-year-old Shields stopped Nikki Adler (then 16-0) in the fifth round and out-boxed Tori Nelson (17-0-3) in each of her last two fights. Costa Rica’s Gabriels (18-1-1, 11 KOs) was knocked out in the second round by Oxandia Castillo in February 2013, but she avenged that setback by out-pointing the Dominican Republic’s Castillo (16-3-3, 13 KOs) in their 10-rounder October 13.

“This will be my toughest fight,” Shields said. “She’s the most skilled and has the most experience. She’s a three-time world champion. I’ve fought former world champions, but she’s a three-time world champion to date. The girl that beat her, Hanna avenged that loss. I’m looking forward to her coming out and putting 100 percent in, and I hope for us to have a great fight. I’m always confident going into fights. I’m not leaving the ring without having two new belts.”

Shields, a two-time Olympic gold medalist from Flint, Michigan, and Gabriels will fight for the vacant IBF and WBA middleweight titles in the main event of a “ShoBox” tripleheader from Masonic Temple.

“You are going to see a very technical and aggressive fighter,” Gabriels said. “That’s the only way that you can fight Claressa because she’s so aggressive herself and so tough, you can’t go in the ring passive against her. You have to put your life on the line in there and that’s what I’m planning to do.”

Showtime’s telecast also will include another women’s middleweight title fight. Germany’s Christina Hammer (22-0, 10 KOs) is set to defend her WBC and WBO crowns against Nelson, of Ashburn, Virginia, in that bout.

If Shields and Hammer win Friday night, they’re expected to meet next in a middleweight championship unification fight.

A 10-round light heavyweight bout between Russia’s Umar Salamov (20-1, 15 KOs) and Atlanta’s Brian Howard (13-1, 10 KOs) also will be broadcast by Showtime on Friday night. The tripleheader is scheduled to begin at 10 p.m. ET/PT.

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