Milos Raonic kept his cool to reach the quarter-finals Monday as young Alexander Zverev went into meltdown and crashed out of the Australian Open.

The fourth seed erupted in frustration and fury during the second set of a 6-1, 6-1, 7-6 (7/5) drubbing by the Canadian 16th seed, hammering his racquet into the ground eight times to leave it a mangled mess.

“I just tried to stay composed, “said Raonic. “It worked extremely well for me today.

“I played incredibly good, did a lot of things extremely well.”

Zverev was tipped as a future Grand Slam champion after a breakthrough 2018 that saw him win the ATP Tour Finals, beating Novak Djokovic and Roger Federer in the process.

Instead it was a familiar tale of woe as his much vaunted-talent deserted him again before he could reach the sharp end of a major.

The 21-year-old’s miserable record in Slams was extended to just one quarter-final, at the French Open last year, in 15 appearances.

All seemed well when the world number four broke former world number three Raonic’s formidable serve in the opening game of the match.

“I was glad I turned around that start quickly,” said Raonic. “I gave myself a lot of curse words after the first game.”

But he then lost the next nine in an error-strewn display.

Zverev committed eight double faults and 16 unforced errors against only eight winners as the first two sets evaporated in 63 minutes.

When he dropped his serve to go 4-1 behind in the second set his seething anger was taken out on his unfortunate racquet, earning a code violation from umpire Carlos Ramos.

Zverev left the court for a bathroom break at the end of the set to let off steam and was at least competitive when he returned.

He stopped the flood of mistakes in the third set and took it to a tiebreak, saving two match points along the way.

But it was too little, too late as Zverev’s abject record in Slams continued.

Instead Raonic, who lost to Andy Murray in the last four in Melbourne in 2016, moves on to face Borna Coric or Lucas Pouille in the quarter-finals.