Melbourne - Croatia's Marin Cilic survived a titanic battle with tyro Bernard Tomic to reach the third round of the Australian Open on Wednesday.
The tournament's 14th seed was pushed to the brink by the 17-year-old Australian before his superior experience helped him seal a 6-7 6-3 4-6 6-2 6-4 victory.
Cilic, who is undefeated this year after successfully defending his title in Chennai, twice fought his way back from a set down and then fought off three break points late in the fifth set before getting the vital break himself.
"I feel very tired," Cilic said after a match that lasted almost four hours and did not finish until after 2am local time.
"We had a lot of long rallies right from the beginning of the match.
"The last set was a physical battle and I won because I've had more matches than him."
Despite his loss, Tomic displayed composure beyond his tender years and enhanced his reputation as Australia's heir apparent to Lleyton Hewitt, who has been struggling with injuries and starting to slip down the rankings.
Australia have been anxious to find another man to lead the next generation and the Gold Coast teenager looms as the obvious candidate after winning the Australian Open junior title in 2008 then making a spectacular debut at the senior event last year.
Given a wildcard entry, the then 16-year-old became the youngest man in professional tennis to win a match at the Australian Open when he defeated Italy's Potito Starace 7-6 1-6 7-6 7-6.
He won last year's U.S. Open junior title and has risen almost 500 places in the world rankings to 289 but needed another wildcard to get into the first grand slam of 2010.
Tomic won his opening match against French qualifier Guillaume Rufin and although he came up short against Cilic, the Croatian said it would not be long before he was regularly beating senior players.
"He's very uncomfortable to play," Cilic said. "His serve is good and he hits a lot of flat balls.
"He knows how to play, he doesn't miss very much and I think he's going to be very hard to beat."
Results from day three of the Australian Open at Melbourne Park on Wednesday (x = seeding):
Marin Cilic (CRO x14) bt Bernard Tomic (AUS) 6-7 (6/8), 6-3, 4-6, 6-2, 6-4
Fernando Gonzalez (CHI x11) bt Marsel Ilhan (TUR) 6-3, 6-4, 7-5
Andy Roddick (USA x7) bt Thomaz Bellucci (BRA) 6-3, 6-4, 6-4
Evgeny Korolev (KAZ) bt Tomas Berdych (CZE x21) 6-4, 6-4, 7-5
Rafael Nadal (ESP x2) bt Lukas Lacko (SVK) 6-2, 6-2, 6-2
Feliciano Lopez (ESP) bt Rainer Schuettler (GER) 6-3, 2-6, 6-3, 6-2
Stanislas Wawrinka (SUI x19) bt Igor Kunitysn (RUS) 6-3, 6-2, 6-2
John Isner (USA x33) bt Louk Sorenson (IRL) 6-3, 7-6 (7/4), 7-5
Philipp Kohlschreiber (GER x27) bt Wayne Odesnik (USA) 6-4, 3-6, 6-3, 6-2
Ivan Ljubicic (CRO x24) bt Andrey Golubev (KAZ) 6-3, 3-6, 6-2, 6-3
Florian Mayer (GER) bt Viktor Troicki (SRB x29) 4-6, 6-4, 7-6 (7/2), 6-1
Gael Monfils (FRA x12) bt Antonio Veic (CRO) 6-4, 6-4, 6-4
Andy Murray (GBR x5) bt Marc Gicquel (FRA) 6-1, 6-4, 6-3
Ivo Karlovic (CRO) bt Julian Benneteau (FRA) 2-6, 6-1, 6-3, 6-3
Juan Martin Del Potro (ESP x4) bt James Blake (USA) 6-4, 6-7 (3/7), 5-7, 6-3, 10-8
Florent Serra (FRA) bt Jarkko Niemenen (FIN) 3-6, 6-4, 5-7, 7-6 (7/4), 7-5
Li Na (CHN x16) bt Marina Erakovic (NZL) 6-2, 6-0
Vera Zvonareva (RUS x9) bt Kristina Kucova (SVK) 6-2, 6-0
Victoria Azarenka (BLR x7) bt Stephanie Cohen-Aloro (FRA) 6-2, 6-0
Agnes Szavay (HUN) bt Stephanie Dubois (CAN) 6-3, 6-2
Iveta Benesova (CZE) bt Chang Kai-Chen (TPE) 7-5, 6-2
Yaroslava Shvedova (KAZ) bt Kimiko Date Krumm (JPN) 6-4, 6-2
Caroline Wozniacki (DEN x4) bt Aleksandra Wozniak (CAN) 6-4, 6-2
Tsvetana Pironkova (BUL) bt Galina Voskoboeva (KAZ) 6-4, 6-4
Julia Goerges (GER) bt Tamira Paszek (AUT) 6-0, 3-6, 6-3
Tathiana Garbin (ITA) bt Elena Vesnina (RUS x28) 7-6 (7/5), 6-4
Shahar Peer (ISR x29) bt Lucie Hradecka (CZE) 6-7 (5/7), 6-2, 6-1
Sofia Arvidsson (SWE) bt Jarmila Groth (AUS) 6-2, 4-6, 6-4
Daniela Hantuchova (SVK x22) bt Viktoriya Kutuzova (UKR) 3-6, 6-1, 7-5
Stefanie Voegele (SUI) bt Melinda Czink (HUN) 7-5, 6-7 (5/7), 9-7
Svetlana Kuznetsova (RUS x3) bt Anastasia Pavlyuchenkova (RUS) 6-2, 6-2
Elena Baltacha (GBR) bt Kateryna Bondarenko (UKR x30) 6-2, 7-5
Kim Clijsters (BEL x15) bt Tamarine Tanasugarn (THA) 6-3 6-3
Marion Bartoli (FRA x11) bt Sandra Zahlavova (CZE) 6-4, 6-4
Zheng Jie (CHN) bt Maria Jose Martinez Sanchez (ESP x24) 2-6, 6-2, 6-3
Nadia Petrova (RUS x19) bt Kaia Kanepi (EST) 6-4, 6-4
Yanina Wickmayer (BEL) bt Flavia Pennetta (ITA x12) 7-6 (7-2), 6-1
Maria Kirilenko (RUS) bt Yvonne Meusburger (AUT) 6-3, 6-1
Angelique Kerber (GER) bt Aravane Rezai (FRA x26) 6-2, 6-3
Sara Errani (ITA) bt Ekaterina Makarova (RUS) 6-2, 6-3
Alona Bondarenko (UKR x31) bt Polona Hercog (SLO) 6-4, 7-5
Dinara Safina (RUS x2) bt Barbora Zahlavova Strycova (CZE) 6-3, 6-4
Alisa Kleybanova (RUS x27) bt Sorana Cirstea (ROM) 6-4, 6-3
Jelena Jankovic (SRB x8) bt Katie O'Brien (GBR) 6-2, 6-2
Roberta Vinci (ITA) bt Vania King (USA) 7-6 (9/7), 7-5
Justine Henin (BEL) bt Elena Dementieva (RUS x5) 7-5, 7-6 (8/6)