MELBOURNE, Australia (AP) ― Maria Sharapova survived the searing heat and an intense challenge from Karin Knapp to advance to the third round of the Australian Open with a grueling 6-3, 4-6, 10-8 win in 3 hours, 28 minutes.

The temperature was forecast to spike at 44 degrees Celsius Thursday, on the third straight day of a heat wave. It was already 39 degrees when Sharapova’s match started and increased to 42.5 degrees, forcing organizers to enact the Extreme Heat Policy and suspend matches on outside courts.

Sharapova wasted three match points on serve at 5-4 in the third set, and then had to save break points and serve to stay in the match before getting the crucial break in the 17th game of the deciding set.

Despite serving three double-faults in the last game, the third-seeded Sharapova held on to win on her fourth match point 50 minutes later when Knapp made consecutive errors at deuce.

“It’s tough for both of us. We fought as hard as we could,” Sharapova said. “She played some of the best tennis I’ve seen her play.”

Sharapova, playing her second tournament back from extended time off for a right shoulder injury, wore ice vests in every changeover after the third game, draped ice bags over shoulders and poured water over her head. Sharapova recalled a first-round match in sauna-like conditions in Australia in 2007 that she won 9-7 in the third against Camille Pin and where “I remember being really close to passing out.”

“I’m feeling much better now,” she said.

She’ll next meet No. 25 Alize Cornet of France, who sobbed on court after coming back to beat Camila Giorgi of Italy 6-3, 4-6, 6-4 in 2 1/2 hours.

“I think I spent enough time on this court for today,” Cornet said in her on-court interview. “I went really further than my limits. It was really hot, that’s why I’m so emotional.”

“Doing something physical in this heat it’s just unbelievable.”

No. 29 Anastasia Pavlyuchenkova also complained about the heat after her 6-2, 6-2 win over Mandy Minella.

Pavlyuchenkova finished in 1 hour, 17 minutes, but said it still took a toll. She said she nearly passed out on court in her first-round match.

“It’s really tough to play your best,” she said. “When you get a little bit of heat stroke your body feels really heavy.

“My body was really hot, you feel sluggish, and you get frustrated because you can’t play your good tennis.”

No. 11 Simona Halep had a 4-6, 6-0, 6-1 win over American Varvara Lepchenko, who only won one game after needing treatment for heat-related problems late in the second set.

Former No. 1-ranked Caroline Wozniacki advanced to the third round of the Australian Open in the relatively comfortable confines of a roof-covered Rod Laver Arena, beating American Christina McHale 6-0, 1-6, 6-2.

Also, Roger Federer played his first Australian Open match away from Rod Laver Arena in a decade and beat Blaz Kavcic of Slovenia 6-2, 6-1, 7-6 (4) to reach the third round at Melbourne Park.

Federer had played 63 matches in a row at Rod Laver Arena until being assigned to the secondary 10,000-seat Hisense Arena for Thursday’s match.

The former No. 1-ranked but now sixth-seeded Federer won the first of four Australian Open titles in 2004 and hasn’t played anywhere except the 15,000-seat center court since then at Melbourne Park.