American fifth seed Sloane Stephens has ended the Australian Open campaign of her former junior doubles partner Timea Babos.
Stephens triumphed 6-3 6-1 although the second-round victory was a more hard- fought one than suggested by the scoreline.
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Hungarian Babos was down break point on 23 occasions, but Stephens was only able to convert five of them in a match which lasted one hour and 35 minutes.
"We were friends when we played juniors, we practised together and stuff, but I don't know how that came to pass," said Stephens of her successful partnership with Babos which netted three junior grand slam doubles titles in 2010.
"I still see her every week. We're good.
"She's obviously an incredible doubles player - last year she was No.1 in the world.
"She had some really good results and I'm happy for her."
Stephens enjoyed her grand slam breakthrough at the 2013 Australian Open, when she beat Serena Williams to advance to the semis as a 19-year-old.
But it has been more of a case of slim pickings in recent times, with the victory over Babos only her third at Melbourne Park in the past five years.
"I thought it was a good match and obviously it's not easy playing someone who serves like that," said the 2017 US Open champion.
"I am feeling relaxed considering I hadn't won a match here in I don't know how long."
Stephens' third-round opponent will be Croatian No.31 seed Petra Martic, who ousted Czech Marketa Vondrousova 6-4 7-5.
Local hope Ashleigh Barty has powered to another straight-sets win to storm into the third round.
The Australian number one and 15th seed fired seven aces and dropped serve only once in an impressive 6-2 6-3 win over China's Yafan Wang on Wednesday.
A finalist at last week's Sydney International, the 22-year-old has surged into fourth favouritism to become the first home winner of the Open since Chris O'Neill in 1978.
Barty, though, insisted the hype was easy to block out.
"I don't read the papers to start off with," she said.
"I can come out here and play with freedom.
"When I'm playing well, I'm really enjoying myself out on court and that is all I can ask of every match.
"If I win, it's a bonus. If I lose, the sun still comes up the next day and it's all good."
Barty will play either West Australian qualifier Astra Sharma or Greek Maria Sakkari on Friday for a place in the second week of the Open for the first time.
In other early action on Wednesday, French No.19 seed Caroline Garcia eased past Australian wildcard Zoe Hives 6-3 6-3.
Russian Anastasia Pavlyuchenkova upset No.9 seed Kiki Bertens from the Netherlands 3-6 6-3 6-3.
Belarusian Aliaksandra Sasnovich also ousted a seed, beating No.20 Anett Kontaveit from Estonia 6-3 6-3.
Other second round women's draw results:
Danielle Collins (USA) bt Sachia Vickery (USA) 6-3 7-5
Amanda Anisimova (USA) bt 24-Lesia Tsurenko (UKR) 6-0 6-2
Maria Sakkari (GRE) bt Q-Astra Sharma (AUS) 6-1 6-4