It’s been a long time since the opening odds were this close for a Cris Cyborg fight.

On Wednesday, the highly anticipated super fight between UFC women’s featherweight champion Cyborg and bantamweight champion Amanda Nunes became official. After months of talk, a date has been set for Cyborg to put her 145-pound title on the line at UFC 232 on Dec. 29 from T-Mobile Arena in Las Vegas.

Nunes (16-4 MMA, 9-1 UFC) figures to be the biggest challenge Cyborg (20-1 MMA, 5-0 UFC) has faced in years, which is how the oddsmakers see it.

Online betting site OddsShark.com has set the opening line at Cyborg being a -300 favorite with Nunes coming back +230. At these odds, a winning $100 bet on Cyborg would net a profit of $33.33 (implied win probability of 75 percent). Meanwhile, a winning $100 bet on Nunes would make a profit of $230 (implied win probability of 30.3 percent).

Not since Cyborg’s 2009 showdown with Gina Carano for the inaugural Strikeforce women’s featherweight title have the odds been so close for one of her fights. Both women opened at -115 back then.

The 33-year-old Cyborg, whose only loss came in her 2005 professional debut, aims for her third UFC title defense. She most recently TKO’d Yana Kunitskaya in the first round at UFC 222 in March. Prior to that she won a unanimous decision against Holly Holm in December.

Nunes, 30, will look to become the first women’s champ-champ in UFC history. She’s currently on a seven-fight winning streak that dates back to March 2015. Since winning the bantamweight title from Miesha Tate in July 2016, Nunes has defended it three times – against Ronda Rousey, Valentina Shevchenko last year, and Raquel Pennington in May.

For more on UFC 232, visit the UFC Rumors section of the site.