Melbourne - Alexander Zverev almost blew his quest for a maiden Grand Slam title on Thursday but said he would learn from the experience of coming through a five-set Australian Open win over France's Jeremy Chardy.
The fourth seed looked far from his anointed status as the flag-bearer for the next generation as he failed time and again to put away the veteran in round two before winning 7-6 (7/5), 6-4, 5-7, 6-7 (6/8), 6-1.
The 21-year-old will face young Australian wildcard Alex Bolt in the last 32 after eventually prevailing in 3hr 42min on Margaret Court Arena.
Watched by concerned coach Ivan Lendl, Zverev threw away four break points in the third set and four more and a match point in the fourth.
"I thought the match was very high quality, high level," Zverev told reporters. "Jeremy started playing really, really well in the third and fourth set."
The dogged Frenchman, the world number 36, simply wouldn't lie down and extended the match beyond midnight with Zverev finally securing match point at 12:15am local time Friday (13:15 GMT Thursday) as the two embraced warmly at the net.
"I knew if I stayed strong, if I keep doing what I'm doing, I'll get my chances," said Zverev.
"I actually had my chances in all sets. Didn't manage to break. Matches can turn around quickly. I'm just happy to be in the third round."
In-form Zverev began the year with a run to the final of the mixed teams Hopman Cup following his breakthrough victory over Novak Djokovic at the ATP Tour Finals last season.
The young German said the experience of coming through a tough five-setter would benefit him in the future.
"I mean, it was good," he said. "I was never two sets to love up and then two sets all.
"That was my first time today. It was definitely helpful that I won this match. I'm still in the tournament, first of all, but also for myself it's very helpful, as well."
But he knows he needs to win a Grand Slam soon to cement his place as a serious contender to end the major monopoly enjoyed by the old guard of Roger Federer, Rafael Nadal and Djokovic.
So far, he has reached just one quarter-final in 14 appearances on the game's biggest stages, losing to Dominic Thiem in the last eight at the 2018 French Open despite having won 10 ATP titles.
He has never got beyond the third round in Melbourne. Last year, seeded four, he crashed out at that stage to South Korea's Chung Hyeon.
Collated results from Day 4 of the Australian Open on Thursday:
Kei Nishikori (JPN x8) bt Ivo Karlovic (CRO) 6-3, 7-6 (8/6), 5-7, 5-7, 7-6 (10/7)
Borna Coric (CRO x11) bt Marton Fucsovics (HUN) 6-4, 6-3, 6-4
Pablo Carreno-Busta (ESP x23) bt Ilya Ivashka (BLR) 6-2, 6-3, 7-6 (9/7)
Fabio Fognini (ITA x12) bt Leonardo Mayer (ARG) 7-6 (7/3), 6-3, 7-6 (7/5)
Joao Sousa (POR) bt Philipp Kohlschreiber (GER x32) 7-5, 4-6, 7-6 (7/4), 5-7, 6-4
Pierre-Hugues Herbert (FRA) bt Chung Hyeon (KOR x24) 6-2, 1-6, 6-2, 6-4
Milos Raonic (CAN x16) bt Stan Wawrinka (SUI) 6-7 (4/7), 7-6 (8/6), 7-6 (13/11), 7-6 (7/5)
Denis Shapovalov (CAN x25) bt Taro Daniel (JPN) 6-3, 7-6 (7/2), 6-3
David Goffin (BEL x21) bt Marius Copil (ROU) 5-7, 7-5, 6-2, 6-4
Daniil Medvedev (RUS x15) bt Ryan Harrison (USA) 6-3, 6-3, 6-3
Filip Krajinovic (SRB) bt Evgeny Donskoy (RUS) 6-4, 7-6 (10/8), 7-6 (7/2)
Alexei Popyrin (AUS) bt Dominic Thiem (AUT x7) 7-5, 6-4, 2-0 retired
Alex Bolt (AUS) bt Gilles Simon (FRA x29) 2-6, 6-4, 4-6, 7-6 (10/8), 6-4
Lucas Pouille (FRA x28) bt Maximilian Marterer (GER) 7-6 (10/8), 7-6 (10/8), 5-7, 6-4
Novak Djokovic (SRB x1) bt Jo-Wilfried Tsonga (FRA) 6-3, 7-5, 6-4
Alexander Zverev (GER x4) bt Jérémy Chardy (FRA) 7-6 (7/5), 6-4, 5-7, 6-7 (6/8), 6-1
Camila Giorgi (ITA x27) bt Iga Swiatek (POL) 6-2, 6-0
Wang Qiang (CHN x21) bt Aleksandra Krunic (SRB) 6-2, 6-3
Elina Svitolina (UKR x6) bt Viktoria Kuzmova (SVK) 6-4, 6-1
Karolina Pliskova (CZE x7) bt Madison Brengle (USA) 4-6, 6-1, 6-0
Anastasija Sevastova (LAT x13) bt Bianca Andreescu (CAN) 6-3, 3-6, 6-2
Elise Mertens (BEL x12) bt Margarita Gasparyan (RUS) 6-1, 7-5
Hsieh Su-wei (TPE x28) bt Laura Siegemund (GER) 6-3, 6-4
Madison Keys (USA x17) bt Anastasia Potapova (RUS) 6-3, 6-4
Timea Bacsinszky (SUI) bt Natalia Vikhlyantseva (RUS) 6-2, 7-5
Naomi Osaka (JPN x4) bt Tamara Zidansek (SLO) 6-2, 6-4
Zhang Shuai (CHN) bt Kristyna Pliskova (CZE) 6-3, 7-5
Simona Halep (ROU x1) bt Sofia Kenin (USA) 6-3, 6-7 (5/7), 6-4
Venus Williams (USA) bt Alize Cornet (FRA) 6-3, 4-6, 6-0
Dayana Yastremska (UKR) bt Carla Suarez (ESP x23) 6-3, 3-6, 6-1
Serena Williams (USA x16) bt Eugenie Bouchard (CAN) 6-2, 6-2
Garbine Muguruza (ESP x18) bt Johanna Konta (GBR) 6-4, 6-7 (3/7), 7-5