MELBOURNE—Patrick Mouratoglou, the coach of Serena Williams, says the American is ''mentally better" and has "bigger weapons" when playing Maria Sharapova. Williams beat Sharapova in the final of the Australian Open, and has now defeated the Russian 16 times in a row.

“When you beat someone that many times in a row, it means something,” Mouratoglou told the press following the match.

Williams, 33, now owns 19 Grand Slam singles titles, tying her with Helen Wills Moody. Steffi Graf won 22 Grand Slam singles titles, while Australia's Margaret Court owns the all-time record with 24.

Mouratoglou said the record was attainable.

“Of course she can,” said Mouratoglou. “I'm not saying it's going to be easy. For sure it's going to be very difficult. She will have to stay fit, she will have to keep the motivation as high as it is now. She has been playing 17 years on tour, so to wake up every morning, go to practice, all these things.

“But she still has for the moment.”

Mouratoglou has coached Williams for two-and-a-half years.