Alexander Zverev almost blew his quest for a maiden Grand Slam title Thursday before registering a 7-6 (7/5), 6-4, 5-7, 6-7 (6/8), 6-1 win over France’s Jeremy Chardy at the Australian Open on Thursday. He will face young Australian wildcard Alex Bolt in the last 32 after winning in 3hr 42min on Margaret Court Arena.

Meanwhile, top seed Novak Djokovic proved to be too strong in the rematch of the 2008 Australian Open final, beating wildcard Jo-Wilfried Tsonga 6-3, 7-5, 6-4 in the second round.

Japan’s Kei Nishikori blew a two-set lead against veteran Ivo Karlovic 2014 champion Stan Wawrinka was edged out by 16th seed Milos Raonic in the tightest of second-round battles.

Hyeon Chung failed to repeat last year’s giant-killing heroics after crashing out to Pierre-Hugues Herbert in the second round. The 24th seeded South Korean lost 6-2, 1-6, 6-2, 6-4 to the unseeded Frenchman on Melbourne Arena. Herbert will face big-serving Milos Raonic in the third round.

Seventh seed Dominic Thiem retired when 7-5, 6-4, 2-0 down to young wildcard Alexei Popyrin.

The Austrian got through a first round five-setter against Benoit Paire that finished in the early hours of Wednesday morning and he never looked 100 percent against the Australian.

Thiem smashed his racquet at one point and called for the trainer before retiring to hand Popyrin, 19, the biggest win of his fledgling career.

“It’s never easy winning like this, Dom played a tough first round. It’s never easy winning like this,” said the teenager. But he added: “I always thought I was in the match, to be honest.”

The 33-year-old Wawrinka, unseeded for the first time since his debut in 2006 after being plagued by injury, fell to the Canadian after four sets decided on tiebreaks 6-7 (4/7), 7-6 (8/6), 7-6 (13/11), 7-6 (7/5).

Wawrinka was a break up in the fourth set but failed to serve out from 5-4 to take it to a fifth.

“I was fortunate to stay alive in the fourth set,” admitted Raonic, whose best Slam performance was reaching the 2016 Wimbledon final where he lost to Andy Murray. “Four tie-breaks, three went my way,” added the Canadian. “Could easily have been different.”

The Swiss showed more than a few glimpses of his old greatness with his powerful single-handed backhand in full cry. And Wawrinka’s serve powered down 28 aces to Raonic’s 39 during four hours and one minute of blistering play.

The match started under cloudy skies and finished indoors after a mid-match rain delay caused organisers to close the Rod Laver Arena roof.

Giant Croat Karlovic, 39, stood on the brink of becoming the oldest man into the third round since 44-year-old Aussie great Ken Rosewall in 1978 before Nishikori saved three break points at 5-5 in the final set.

Asia’s top-ranked men’s player needed an energy-sapping 3hr 48min to get past big-serving Croat Karlovic 6-3, 7-6 (8/6), 5-7, 5-7, 7-6 (10/7) in humid conditions on Margaret Court Arena.

“It was a tough match which could have gone both ways. He almost had it for sure,” said Nishikori, a three-time quarter-finalist at Melbourne Park, after falling to his knees in relief.

The eighth seed next faces either Philipp Kohlschreiber or Joao Sousa for a place in the last 16.

Chung has struggled to build on his breakout performance where he famously beat fourth seed Alexander Zverev and Djokovic en route to retiring in the second set against Federer with massive, deep blisters on both feet.

Results

2nd round

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