Melbourne - British teenager Laura Robson claimed another big Grand Slam scalp as she outlasted eighth-seeded Czech Petra Kvitova 2-6, 6-3, 11-9 in a late-night thriller at the Australian Open.
The 18-year-old Robson, who beat Kim Clijsters and Li Na at last year's US Open, took advantage of 18 double faults from former Wimbledon champion Kvitova to reach the third round.
"I knew it was going to be very, very tough and trying to return her serve in the first set was very, very hard," 53rd-ranked Robson told the crowd.
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"But I knew once I got my returns firing and a bit more confidence on my serve I could get myself back into the match and that's what I did."
With temperatures still close to 90 degrees as the match moved past midnight, both players made a stack of errors but Robson recovered from 4-2 down to serve for the match at 6-5.
Nerves got to her and Kvitova broke back but Robson broke again in the 19th game and then held on to set up a clash with American 19-year-old Sloane Stephens.
Robson's win, combined with the progress of Heather Watson, means there are two British women in the third round in Melbourne for the first time since 1991.
Results from day four of the Australian Open on Thursday:
Victoria Azarenka (BLR x1) bt Eleni Daniilidou (GRE) 6-1, 6-0
Ayumi Morita (JPN) bt Annika Beck (GER) 6-2, 6-0
Roberta Vinci (ITA x16) bt Akgul Amanmuradova (UZB) 6-3, 6-2
Maria Kirilenko (RUS x14) bt Peng Shuai (CHN) 7-5, 6-2
Elena Vesnina (RUS) bt Varvara Lepchenko (USA x21) 6-4, 6-2
Serena Williams (USA x3) bt Garbine Muguruza (ESP) 6-2, 6-0
Jamie Hampton (USA) bt Luksika Kumkhum (THA) 6-1, 6-2
Lesia Tsurenko (UKR) bt Daria Gavrilova (RUS) 7-5, 6-3
Svetlana Kuznetsova (RUS) bt Hsieh Su-wei (TPE x26) 6-2, 6-1
Yanina Wickmayer (BEL x20) bt Jana Cepelova (SVK) 7-6 (10/8), 7-5
Caroline Wozniacki (DEN x10) bt Donna Vekic (CRO) 6-1, 6-4
Kimiko Date-Krumm (JPN) bt Shahar Peer (ISR) 6-2, 7-5
Carla Suarez Navarro (ESP) bt Yulia Putintseva (KAZ) 1-6, 7-6 (7/5), 6-2
Bojana Jovanovski (SRB) bt Lucie Safarova (CZE x17) 7-5, 7-5
Sloane Stephens (USA x29) bt Kristina Mladenovic (FRA) 6-4, 6-3
Laura Robson (GBR) bt Petra Kvitova (CZE x8) 2-6, 6-3, 11-9
Ricardas Berankis (LTU) bt Florian Mayer (GER x25) 6-2, 6-3, 6-1
Philipp Kohlschreiber (GER x17) bt Amir Weintraub (ISR) 6-2, 7-6 (7/4), 6-4
Jo-Wilfried Tsonga (FRA x7) bt Go Soeda (JPN) 6-3, 7-6 (7/1), 6-3
Andy Murray (GBR x3) bt Joao Sousa (POR) 6-2, 6-2, 6-4
Milos Raonic (CAN x13) bt Lukas Rosol (CZE) 7-6 (7/2), 6-2, 6-3
Marin Cilic (CRO x12) bt Rajeev Ram (USA) 7-5, 6-2, 6-4
Blaz Kavcic (SLO) bt James Duckworth (AUS) 3-6, 6-3, 6-4, 6-7 (3/7), 10-8
Bernard Tomic (AUS) bt Daniel Brands (GER) 6-7 (4/7), 7-5, 7-6 (7/3), 7-6 (10/8)
Andreas Seppi (ITA x21) bt Denis Istomin (UZB) 7-6 (7/4), 5-7, 6-7 (3/7), 7-6 (7/3), 6-2
Juan Martin Del Potro (ARG x6) bt Benjamin Becker (GER) 6-2, 6-4, 6-2
Gael Monfils (FRA) bt Lu Yen-hsun (TPE) 7-6 (7/5), 4-6, 0-6, 6-1, 8-6
Gilles Simon (FRA x14) bt Jesse Levine (CAN) 2-m6, 6-3, 7-6 (7/4), 6-2
Jeremy Chardy (FRA) bt Marcel Granollers (ESP x30) 6-3, 3-6, 6-1, 6-2
Roger Federer (SUI x2) bt Nikolay Davydenko (RUS) 6-3, 6-4, 6-4
Richard Gasquet (FRA x9) bt Alejandro Falla (COL) 6-3, 6-2, 6-2
Ivan Dodig (CRO) bt Jarkko Nieminen (FIN) 6-3, 6-7 (4/7), 6-3, 6-7 (4/7), 6-1