Serena Williams and Victoria Azarenka advanced in contrasting styles on Saturday to the fourth round at the Australian Open.

Williams recovered from a break down in the second set to win six straight games and finish off a 6-1, 6-3 win over Japan’s Ayumi Morita in 66 minutes.

Azarenka struggled to hold off injured American Jamie Hampton 6-4, 4-6, 6-2 and she didn’t help herself with six double-faults. At least she survived.

Chardy shocks del Potro

Juan Martin del Potro, the 2009 US Open champion, lost a marathon match 6-3, 6-3, 6-7(3), 3-6, 6-3 to Jeremy Chardy of France, leaving only three major winners in the men’s draw. Chardy will next face Andreas Seppi, who ousted No. 12 Marin Cilic with a 6-7 (2), 6-3, 2-6, 6-4, 6-2 victory.

“I feel so much emotion. Five sets, to be here in a Grand Slam. It’s the most beautiful match of my career,” Chardy said. “It’s a great moment for me, everyone dreams of this.”

Andy Murray advanced with a gritty 6-3, 6-4, 7-5 win over Lithuanian qualifier Ricardas Berankis.

Murray admitted to episode of frustration in a windy win, with one side of the Rod Laver arena court playing differently than the other.

“You had to do a lot of running on one side,” said the third seed. “On the other side you had to play with more spin or else the ball would fly. It was tricky conditions today.

“In the second set he was making me feel pretty uncomfortable, I was getting frustrated. The court is playing very quick. I need to strike the ball better, my timing is off. I must work on that in training.”

A pair of Frenchmen advanced and will meet in the fourth round, with No. 7 Jo-Wilfried Tsonga beating Slovenia’s Blaz Kavcic 6-2, 6-1, 6-4 to set up a meeting with No. 9 Richard Gasquet, who fended off Croatia’s Ivan Dodig 4-6, 6-3, 7-6 (2), 6-0.

Williams surprised herself with another serve at 128 mph in an afternoon match on Rod Laver Arena, matching a career best that she hit earlier in the tournament.

“I tried to hit it really hard. I hit 207 (kph) the other day and I thought it was luck,” she said. “But I did it again and I was like, ‘Whew! I’m going to try to go for 210.’ We’ll see.”

Azarenka appeared frustrated at times, but overcame an early break and fended off triple break point in the seventh game of the deciding set before clinching the match in 2 hours, 9 minutes.

“She played incredible, went for every single shot. I felt it was touching every single line,” Azarenka said. “She took a medical timeout but she rips winners all over the place and I was like, ‘Can I have a back problem?’ I’m feeling great, but I’m missing every shot.”

After wasting two set points on Azarenka’s serve late in the second set, Hampton had to leave the court for nine minutes to have treatment on her back.

Azarenka practiced her backhands and serve while Hampton was in the locker room, but the break didn’t help her immediately. Hampton returned and held in the next game and needed more treatment in the break at the end of the set.

Even with the pain of two herniated disks, Hampton went down swinging making 47 unforced errors to go with the winners that caught Azarenka off guard and had her asking, loudly at one point, what she could do to counter them.

Bhupathi, Paes advance

Bhupathi and his Canadian partner Daniel Nestor defeated Romania’s Victor Hanescu and Slovak Martin Klizan 6-1, 7-6 (8) to enter the third round.

They next face Simone Bolelli and Fabio Fognini, who shocked Rohan Bopanna and Rajeev Ram 6-2, 7-6 (3).

Paes and Elena Vesnina overcame a stiff resistance from Aisam-Ul-Haq Qureshi and Sofia Arvidsson in the first round.

The second-seeded Indo-Russian pair came from behind to edge past the unseeded rivals 6-7 (8), 6-4, 10-7. They next take on Australian pair of Jarmila Gajdosova and Matthew Ebden.

Bopanna and Chinese Taipei’s Su-Wei Hsieh defeated Australian-American pairing of Ashleigh Barty and Jack Sock 6-3, 6-3.

Wozniacki through

Serena will meet No. 14 Maria Kirilenko in the fourth round, who beat No. 20 Yanina Wickmayer 7-6 (4), 6-3. Azarenka next plays Elena Vesnina, who beat Roberta Vinci of Italy 7-6 (4), 6-4.

Two-time major winner Svetlana Kuznetsova continued her comeback from injury with a 6-2, 4-6, 6-3 win over Spain’s Carla Suarez Navarro and advanced to a fourth round match with former No. 1 Caroline Wozniacki, a 6-4, 6-3 winner against Lesia Tsurenko.

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