MADRID (AP) — Serena Williams kept the number one, and added number 50.

Williams beat Maria Sharapova 6-1, 6-4 in the final of the Madrid Open yesterday to retain her number one ranking and collect her 50th career title, while Rafael Nadal saw off Stanislas Wawrinka 6-2, 6-4 for his fifth title since returning from a knee injury.

The second-ranked Sharapova would have taken the top ranking with a win, but Williams stormed to an early lead as Sharapova struggled with her serve.

Despite Sharapova briefly recovering her poise in the second set, Williams’ form never dipped as she defended her title.

“It feels good,” Williams said of winning her 50th title. “I don’t know how many more I can win. Who knows if I will ever win another title? I just want to live the dream. Hopefully, I can keep it going.

“When you first start out everything is so exciting. Now I expect to win.”

Williams improved her record against Sharapova to 13-2, with her only two losses coming in 2004.

The 31-year-old Williams, playing in her first red clay final since 2002, dominated Sharapova from the start as the Russian never managed to steady her erratic serve.

Sharapova committed five double faults in her first three service games, dropping the first two as Williams eased to a one-set lead. Her shaky serve let Williams gear up and land several winning shots before closing out the first set with a floating return that clipped the line.

Sharapova earned and converted her first break point to begin the second set, opening up a 3-1 advantage.

But the former number one-ranked player’s serve again betrayed her as she hit another double fault, and Williams’ precise groundstrokes set up three break points to hit right back.

Williams closed out the final after Sharapova recorded her eighth and final double fault before sending the ball long to give up her fifth service game.

Cheered on by the home crowd at the Caja Magica, the fifth-ranked Nadal cruised to his 55th career title and extended his head-to-head record with Wawrinka to 9-0.

Nadal flopped on his back and screamed in joy when his Swiss opponent’s final volley fell long to end the match.

It was Nadal’s seventh straight final since coming back from a nagging case of tendinitis in his left knee that sidelined him for seven months.

“I’m very happy and maybe this victory is even more special considering how complicated this year has been,” said Nadal. “This tournament couldn’t have gone better for me.

“I think this was my best match of the tournament. This was perhaps the match where I was the most aggressive.”