After reaching her 37th Grand Slam singles semi-final, she returned with Britain's Andy Murray in a fist-pumping, high-fiving, forehand-slapping frenzy as the mixed doubles 'Dream Team' put on a show for the thousands of fans who had hung around into the evening to watch.

'SerAndy' or 'Murrena', as the multiple Grand Slam-winning duo have been dubbed, eased into the third round with a 7-5 6-3 win over America's Raquel Atawo and France's Fabrice Martin.

Having beaten compatriot Alison Riske in three sets in the singles quarter-finals earlier in the day, Williams looked like she wanted to be anywhere but out on court again.

Not in a sulky sort of way. Far from it. She was in a fired-up frenzy to get off court as fast as possible as the evening drew in, smashing winners left and right, roaring, fist-pumping and pirouetting in celebration as each one flew off her racket.

"I am having a blast," she said. "Obviously it has been a great atmosphere playing out there with Andy, so it is great."

Any doubt over whether Williams would be in the mood for the mixed doubles was dispelled in the first game as she smashed a volley straight at Martin, apologizing profusely after the ball cannoned off his body.

Playing with home favorite Murray, a twice Wimbledon singles champion, means Williams had the Centre Court crowd firmly in her corner and they loudly roared their approval throughout as she fired a string of superb return winners.

"I do not expect that to ever happen again. I'm convinced that was once in a lifetime. I just never hit returns like that in my life," said Williams.

The result of the match was never really in doubt, even if the first set was tight - but this partnership was never meant to be just about results.

Both players are using the mixed doubles as an opportunity to play matches in an effort to return from injuries, with Williams feeling her way back after a niggling knee problem and Murray feeling his way after hip surgery.

Williams' focus will return to her main task on Thursday when the 11th seeded American faces unseeded Czech Barbora Strycova in the semi-finals as she bids to claim a record-equalling 24th Grand Slam singles title.

Murray, however, is playing the long game, having made no immediate decision about when he will be ready to battle again with the likes of Novak Djokovic, Rafa Nadal and Roger Federer.

(Reporting by Toby Davis; Editing by Ken Ferris)

By Toby Davis