LAS VEGAS -- He beat Oscar De La Hoya in his last fight and has a promise to fight Felix Trinidad next.

So what motivates Shane Mosley for his fight tonight with Winky Wright? Plenty.

There's the lure of winning another belt and becoming the undisputed 154-pound champion. There's a desire to prove he can punch as well as box.

And finally, there's that little issue of $10 million -- the money he'll earn to fight Trinidad in November if he wins.

"For me to get to Trinidad, I have to beat Winky," Mosley said. "I've got my mind very focused on Winky Wright. I'll think about Trinidad right after the victory."

Mosley is taking a big chance when he meets Wright in a scheduled 12-round fight tonight that will unify the 154 pound title. It's a chance he didn't have to take after winning the biggest fight of his career in September against De La Hoya.

For Wright, there's nothing but upside in trying to prove he is a true champion. For Mosley, the perils outweigh the rewards, but that didn't stop him from seeking the fight.

"My main thing is just being the undisputed champion, the best guy out there," Mosley said. "I'm not ducking anyone."

A lot of other fighters have ducked Wright, a tall southpaw who tends to make his opponents look bad. Wright nearly beat Fernando Vargas in 1999. He holds the IBF version of the 154-pound title and is finally getting the big fight he has wanted for so long.

The two meet in a scheduled 12-round fight at Mandalay Bay hotel-casino with Mosley's WBC and WBA titles on the line along with Wright's IBF crown. Also on the card is a fight between unbeaten heavyweight prospect Joe Mesi and former cruiserweight champion Vassiliy Jirov.

"It's a better win situation for Winky," Mosley acknowledged. "But it's history winning all three belts, taking care of all the belts in the division and then moving on to the next challenger."

Mosley (39-2, 35 knockouts) signed to meet Wright before Trinidad agreed to come out of retirement to meet him in November. He doesn't regret taking the fight, though his purse will be far smaller than what he'll make against Trinidad or in a third fight against de la Hoya.

Negotiations for that third fight never took off because, Mosley believes, de la Hoya's camp didn't want to give at least equal money to a fighter who had beaten him twice.

Wright, though a 3-1 underdog, presents a lot of challenges to Mosley, who has fought left-handers only twice. He's got a good jab, good ring skills and a burning desire to prove himself on the big stage.

Wright (46-3, 25 knockouts) has defended the IBF title four times. But most of those defenses came on cards headlined by other fighters.

In boxing, left-handers without a big punch often don't sell well.

Wright, who like Mosley is 32, is a rare fighter in that he has fought his whole 14-year pro career at 154 pounds. That's unlike Mosley, who started out as a lightweight and has gone only 15 rounds at his current weight.