Williams surprised by her serving

Serena Williams said she had 'no idea' how well she was serving despite firing a Wimbledon record of 24 aces on her way to the final.

The American sixth seed defeated world number two Victoria Azarenka 6-3 7-6 (8-6) to reach her seventh decider at the All England Club.

Williams cracked 20 aces at Wimbledon against Elena Dementieva in a 2009 semi-final, but has already bettered that twice this year - with 23
against Jie Zheng in the third round and now with her semi-final effort on
Thursday.

The 13-time grand slam winner is aiming for her fifth Wimbledon title.

"I had absolutely no idea. It really didn't feel like I hit 24 aces at all," Williams said.

"I really need to watch this film because I didn't realise that.

"I thought my serve was off, and clearly it wasn't, so maybe I should be off a little more.

"I was just trying to play my game, and my game is pretty aggressive."

Belarusian Azarenka was full of praise for Williams and remained upbeat despite her exit from the tournament.

"She serves 200. That already makes it difficult. I don't see anybody else serving like this on the tour," Azarenka said.

"There is no point to sit and cry how unfortunate I was because she played great.

"I just have to give her all the credit because she did her job.

"I actually take a lot of positive things out of today.

"It was a little bit unfortunate, but I can only learn from here and move on. I don't have any regrets when I walked off the court today."

Williams will meet Polish third seed Agnieszka Radwanska, who accounted for Germany's Angelique Kerber in straight sets, in the final on Saturday.

"Radwanska's been consistent this year, more consistent than I have," Williams said.

"That already tells me from the beginning I really need to go out there, be ready to hit a lot of shots and be ready to play hard.

"She has great hands and she does everything so well. If I come out flat, I won't win."