Serena Williams surprised by record-equalling serve

Serena Williams has expressed her shock at recording the equal-fastest serve of her career for the second time this week at the Australian Open.

The 31-year-old delivered a service of 207kmh during her second-round win over Garbine Muguruza and then repeated the feat as she overcame Japan's Ayumi Morita 6-1 6-3 on Saturday.

"I feel good," said Williams, speaking on court after beating Morita. "I was just really focused. My opponent gave me a good test, but it was good.

"I tried to hit it really hard. I hit 207 the other day and I thought it was luck, but then I did it again.

"I'm targeting 210 now."

Williams has won 15 Grand Slam singles titles.