Nicco Montano is set for her first title defense, but the oddsmakers don’t think much of the UFC women’s flyweight champion’s chances against Valentina Shevchenko.

She’s an underdog. A substantial one. A historic one, even.

As announced on Wednesday, Montano (4-2 MMA, 1-0 UFC) looks for her first title defense when she meets former bantamweight title challenger Shevchenko (15-3 MMA, 4-2 UFC) at UFC 228, which takes place Sept. 9 and airs on pay-per-view from American Airlines Arena in Dallas.

It’s Montano’s first fight since winning the belt by emerging as “The Ultimate Fighter 26” winner in late 2017. By winning the reality-show tournament, Montano, who entered “TUF 26” with just five pro fights, became the inaugural champion of the the UFC’s upstart women’s 125-pound champion.

Despite her own inexperience, Montano picked up some quality wins – over vets Lauren Murphy (10-4 MMA, 2-4 UFC), Montana De La Rosa (9-4 MMA, 2-0 UFC), Barb Honchak (10-4 MMA, 0-2 UFC) and Roxanne Modafferi (22-14 MMA, 1-2 UFC) – during her tourney run. However, it’s not buying her much clout with the oddsmakers.

While lines haven’t opened widely, one book – BetDSI Sportsbook – has posted a pretty lopsided line, with Montano a +360 underdog and Shevchenko a -550 favorite.

At those odds, a winning $100 bet on Montano would result in a net profit of $360 (implied win probability of just 22 percent). A winning $100 bet on Shevchenko, meanwhile, would result in a net profit of just $18.18 (win probability of 85 percent).

According to BetDSI, they’re the worst opening odds for a defending UFC champion in history. Matt Serra’s line to beat Georges St-Pierre eventually closed at +430, though the line wasn’t as wide when odds first opened for the 2008 fight.

For the “TUF 26” tourney final – Montano’s only pro bout with available odds – she closed as a -210 favorite over Modafferi.

Shevchenko, meanwhile, has closed as the favorite in her past three fights – over Priscila Cachoeira (submission win), Amanda Nunes (split-decision loss) and Julianna Pena (submission win).

For more on UFC 228, check out the UFC Rumors section of the site.