Second-seeded Karolina Pliskova hit 10 aces at Olympic Park Tennis Center to oust Russia's Maria Kirilenko, who needed a wild card to enter the tournament she won in 2008.

Maria Sharapova beat former doubles partner and childhood frined Maria Kirlenko 6-4, 6-0 in her opening game at the US Open.

Laura Robson stunned Russian 10th seed Maria Kirilenko with a straight sets win on Tuesday that ensured a female British presence in the second round at Wimbledon.

The defending champion Russian, seeded second this year, survived a nightmare start to hold on to her crown for at least another day with a 0-6, 6-4, 6-3 win over tough Jelena Jankovic in a compelling quarter-final tie.

Whether they are on friendly terms is another matter with the pair enduring an uneasy relationship since those childhood days, although both camps play down talk of a feud.

Kerber, ranked sixth in the world, broke Kudryavtseva 10 times, but dropped her own serve eight times to allow her Russian opponent to stay in the match.

Sharapova, seeking a first title since her 2012 French Open triumph gave her a career Grand Slam, will face former world number one Caroline Wozniacki of Denmark.

Kirilenko, who last year lost to Ana Ivanovic in the final, will take on Sorana Cirstea of Romania on Saturday.

Williams has lost only one match since her first-round exit at the French Open last year. Since then, she has won the Wimbledon, Olympic, U.S. Open, season-ending championship and Brisbane International titles.

There was no stopping the American, with Williams firing down her equal fastest serve of 207 kilometres per hour (128 mph) -- also clocked in round two against Garbine Muguruza -- on her way to taking the set in 31 minutes.