LAS VEGAS – It's hard for Ronda Rousey to top herself, considering she won her first nine fights and finished every one of them en route to becoming the first UFC's women's bantamweight championship.

But she found a way on Saturday by defeating a completely overmatched Alexis Davis in just 16 seconds at the Mandalay Bay Events Center in the co-main event of UFC 175.

It took Rousey longer to get to the cage than it did for her to dispose of Davis. Rousey landed a straight right hand seconds into the match that stunned Davis. She fired a knee to the midsection and then used her judo to throw Davis.

She came down on top of Davis and then landed several powerful punches to the head before referee Yves Lavigne mercifully stopped it.

UFC broadcaster Joe Rogan, interviewing Rousey in the ring, said it wasn't possible for her to be better than she was on Saturday.

Rousey, though, disagreed. "I think I can," she said, and anyone who has watched the arc of her career could hardly disagree with her.

When she started mixed martial arts, her hands were by far her weak point. But after opening her career with eight consecutive finishes by arm bar, Rousey has now stopped her last two opponents with her striking.

She's exceptionally quick and athletic and her boxing is much more fluid now.

Rumors floating out of the Glendale Fight Club where she trains suggest that she's handling high-level women's professional boxers. It's always hard to evaluate such claims, but Rousey is showing fight by fight that her hands are becoming a strength.

"I work on my boxing and striking six days a week and I work on my grappling four days," she said.

She did it Saturday despite potentially breaking a hand. UFC president Dana White tweeted it shortly after the bout ended. Rousey has a cyst under her knuckle of her right hand and she received nine stiches following the fight.

She wasn't even able to enjoy the victory before she was asked if she'd help save another show for the UFC.

UFC 176 is scheduled Aug. 2 in Los Angeles, but featherweight champion Jose Aldo, who was supposed to fight Chad Mendes, was injured and had to pull out. Rumors have abounded that the card would be canceled, but Rogan asked Rousey in the cage if she'd fight on that show against Cat Zingano.

Rousey already came back in 56 days to defeat Sara McMann at UFC 170 after beating Miesha Tate at UFC 168. Rousey said she is dealing with a right knee injury and is scheduled for surgery, but said she'd talk to her coaches and that if they felt she could, she'd take the show.

With the loss of several star level fighters including Georges St-Pierre, Anderson Silva, Cain Velasquez, Nick Diaz and others, Rousey is, in many ways, carrying the UFC on her back.

She's never had anything other than an exciting fight and the crowds have fallen in love with her. There was next-to-no reaction when Davis walked into the ring, just a smattering of polite applause. But the decibel level jumped many notches when Rousey made the ring walk, complete with her trademark pre-fight sneer.

She's already all but cleaned out the bantamweight division, and the only challenger that seems viable at this point is Cris "Cyborg" Justino, who has a rocky relationship with White.

But if Rousey defeats Zingano, if and when they fight, the UFC will have to find someone who can give Rousey even something close to a fight.

And the way Rousey is going, she looks increasingly like she'd handle Justino, as well.

In the main event, middleweight champion Chris Weidman was pushed to the brink, but he survived a fierce challenge from Lyoto Machida to retain his title.

The judges scored the bout 49-45, 49-46 and 48-47 in a fight that had dramatic swings of momentum. Yahoo Sports' card favored Weidman, 48-47.

"He's as good as I thought," Weidman said.

Machida managed to overcome several takedowns by using his elusivity, quick hands and hard kicks to give Weidman a tough fight. Weidman was bleeding from the mouth and had a black and blue mark on his rib cage from Machida's kicks.

But as hard as Machida hit him, Weidman never quit coming. He was a bit stronger and landed a few more hard, clean strikes that made the difference.

"He's a tough opponent and he's the true champion," Machida said. "He deserves the title. I'll be back strong."