Serena Williams overcame a sluggish start to beat Agnieszka Radwanska on Friday in straight sets and reach the Indian Wells tennis final in California.

The world No.1, who will play Victoria Azarenka for the title, was 4-2 down in the opening set and not moving freely in her semi-final, but prevailed 6-4 7-6 (7-1).

The American found her rhythm and won four straight games to claim the set, then continued her run in the second to win the opening three games before her Polish opponent fought back.

Radwanska displayed the tennis that will elevate her to No.2 in Monday’s new world rankings, winning the next three games to get the set back on serve.

The Pole had a chance to win just her second career set against Williams when she broke to lead 6-5, but could not close out.

Williams then erased any Radwanska hopes of claiming a first victory over the American, winning seven straight points to take the tiebreaker 7-1 and improve to 10-0 in their head-to-head battles.

“I think it was really good for me to have a match like that and I think that’s the reason ‘Aga’ is doing so well, because she never gave up,” Williams said.

“I was up so much in the second and she just came back and was determined more than ever, so it was really good to play well against her tonight.

“I could have played three sets but I figured I should at least do 1000 per cent right now. That’s what I tried to do.”

Williams won in 1999 and 2001 at Indian Wells, before a self-imposed 14-year exile from the event amid allegations of racial abuse from fans after sister Venus withdrew minutes before their semi-final showdown.

Fifteen years later, she feels the love.

“I had a lot of support, I heard a lot of ‘Go Serenas’ and that was kind of cool,” Williams added.

“This year has been great. It feels so great to be supported. It’s been a great comeback here in Indian Wells, so I’m excited about that.”

Williams will play 13th seed and 2012 champion Victoria Azarenka. The former world No.1 and two-time Australian Open winner beat Czech Karolina Pliskova 7-6 (7-1) 1-6 6-2 in the other semi.

Despite serving five double faults in the opening set, and a poor second set, Azarenka downed the 18th seed for the chance of a second title this year and a return to the top 10.

“It definitely was a tough battle.

“I’m glad I stayed strong and stayed cool and calm and tried to find a way in the third set to take control.

“I worked so hard this week to put myself in a position to play the best player in the world,” she added about the final.”