Alexander Zverev, who has been tipped as a potential Grand Slam winner and lived up to his billing Tuesday by sweeping into the second round in straight sets while Novak Djokovic began seventh title bid with easy win

Djokovic will face the dangerous unseeded Jo-Wilfried Tsonga in the second round, who the Serb beat in Melbourne to win the first of his 14 Grand Slam crowns back in 2008.

Kei Nishikori survived a dramatic Australian Open first-round match Tuesday after his Polish qualifier opponent retired with cramp in the searing Melbourne heat having raced to a shock two-set lead.

Eighth seed Nishikori of Japan won 3-6, 6-7 (6/8), 6-0, 6-2, 3-0 but the scoreline fails to tell the story of world number 176 Kamil Majchrzak’s torrid end to the match.

The 21-year-old world number four cruised past Aljaz Bedene 6-4, 6-1, 6-4 in 1hr 55min on Rod Laver Arena after coolly overcoming a minor first set blip when he lost his serve to the Slovenian world number 67. The German next faces Jeremy Chardy.

South Korea’s Hyeon Chung beat Novak Djokovic and Alexander Zverev en route to a semi-final last year but was within a whisker of failing to get past the first round.

Cheered on by massed ranks of Korean supporters on Court 8, the 24th seed mounted an epic fightback from two sets down against American Bradley Klahn to win 6-7 (5/7), 6-7 (5/7), 6-3, 6-2, 6-4.

Gritty Chung held both arms aloft and looked to the sky in triumph as he converted on match point after 3hr and 37min and then was swamped by ecstatic fans waving Korean flags and clamouring for autographs as he tried to leave the court.

The 22-year-old, who was the 2017 ATP NextGen Finals champion, was forced to retire from his semi-final last year with eventual champion Roger Federer because of injury.

He will play world number 55 Pierre-Hugues Herbert of France in the second round.

Heart-wrenching sight

Majchrzak had never before played in a Tour-level event other than Davis Cup ties but showed no sign of nerves against Nishikori, who won his 12th ATP Tour at the Brisbane International warm-up.

It was the young Pole’s first ever match against a top 50 opponent but you would never have known it as he took a two-set lead with a succession of blistering winners off both wings.

“I have to say he had it today,” conceded Nishikori. “He played very well and it was unfortunate how it finished.

“I didn’t do anything, but he was hurt and I feel sorry for him.”

At the start of the third set with temperature pushing into the mid 30s Celsius, the 23-year-old began to cramp so badly that he could hardly grip his racquet.

The physio was called and gave Majchrzak some pickle juice to drink after he reported pain in both thighs, both arms and his right hand.

It was a heart-wrenching sight as a tearful Majchrzak was left almost unable to move and the former US Open finalist Nishikori dropped only six points as he professionally eased to the third set 6-0.

Majchrzak had more treatment and was given some medication and massage which helped him emerge for the fourth.

He finally began to regain some movement and broke a run of 10 consecutive losing games to a huge cheer.

But Majchrzak had nothing more in the tank and sensibly called it a day midway through the fifth set leaving Nishikori to thank his lucky stars he made it through.

“I was trying to play but he was playing amazing tennis (in the first two sets),” said Nishikori, who has previously made three Grand Slam semi-finals.

“I have to be happy that I didn’t lose today,” added the Japanese, who missed the Australian Open last year due to a wrist injury.

On his last appearance in 2017, he reached the last-16, falling to Roger Federer in five sets.

The Japan number one will now play Croatian world number 71 Ivo Karlovic who beat Poland’s Hubert Hurkacz 6-7 (5/7), 7-6 (7/5), 7-6 (7/3), 7-6 (7/5).

Elsewhere, 15th seeded Russian Daniil Medvedev went through in three sets while 12th seeded Italian Fabio Fognini beat Spain’s Jaume Munar, who retired with cramps while two sets down.

The 2014 champion Stan Wawrinka also benefited from an opponent pulling out, with Ernests Gulbis calling it quits after hurting his back in the second set.

Results

1st round

Taro Daniel (JPN) bt Thanasi Kokkinakis (AUS) 5-7, 4-2 retired

Denis Shapovalov (CAN x25) bt Pablo Andujar (ESP) 6-2, 6-3, 7-6 (7/3)

David Goffin (BEL x21) bt Christian Garin (CHI) 6-0, 6-2, 6-2

Marius Copil (ROU) bt Marcel Granollers (ESP) 6-3, 6-4, 6-4

Ryan Harrison (USA) bt Jiri Vesely (CZE) 6-0, 7-5, 6-3

Daniil Medvedev (RUS x15) bt Lloyd Harris (RSA) 6-1, 6-2, 6-1

Fabio Fognini (ITA x12) bt Jaume Munar (ESP) 7-6 (7/3), 7-6 (9/7), 3-1 retired

Leonardo Mayer (ARG) bt Nicolas Jarry (CHI) 7-6 (7/4), 7-6 (7/3), 4-6, 6-3

Ilya Ivashka (BLR) bt Malek Jaziri (TUN) 4-6, 7-6 (8/6), 6-1, 4-0 retired

Pablo Carreño-Busta (ESP x23) bt Luca Vanni (ITA) 6-7 (5/7), 2-6, 6-3, 7-5, 6-4

Philipp Kohlschreiber (GER x32) bt Zhe Li (CHN) 6-2, 6-2, 6-4

Joao Sousa (POR) bt Guido Pella (ARG) 7-6 (7/2), 4-6, 7-6 (7/5), 4-6, 6-2

Ivo Karlovic (CRO) bt Hubert Hurkacz (POL) 6-7 (5/7), 7-6 (7/5), 7-6 (7/3), 7-6 (7/5)

Kei Nishikori (JPN x8) bt Kamil Majchrzak (POL) 3-6, 6-7 (6/8), 6-0, 6-2, 3-0 retired

Alexander Zverev (GER x4) bt Aljaz Bedene (SLO) 6-4, 6-1, 6-4

Alex Bolt (AUS) bt Jack Sock (USA) 4-6, 6-3, 6-2, 6-2

Gilles Simon (FRA x29) bt Bjorn Fratangelo (USA) 7-6 (7/2), 6-4, 6-2

Hyeon Chung (KOR x24) bt Bradley Klahn (USA) 6-7 (5/7), 6-7 (5/7), 6-3, 6-2, 6-4

Pierre-Hugues Herbert (FRA) bt Sam Querrey (USA) 5-7, 7-6 (8/6), 6-3, 6-1

Borna Coric (CRO x11) bt Steve Darcis (BEL) 6-1, 6-4, 6-4

Marton Fucsovics (HUN) bt Albert Ramos (ESP) 6-3, 6-4, 6-7 (5/7), 6-3

Evgeny Donskoy (RUS) bt Laslo Djere (SRB) 6-7 (5/7), 6-4, 6-1, 7-6 (7/5)

Lucas Pouille (FRA x28) bt Mikhail Kukushkin (KAZ) 6-1, 7-5, 6-4

Alexei Popyrin (AUS) bt Mischa Zverev (GER) 7-5, 7-6 (9/7), 6-4

Stan Wawrinka (SUI) bt Ernests Gulbis (LAT) 3-6, 3-1 retired