World number one Andy Murray has been knocked out of the Australian Open, sensationally beaten by unseeded German Mischa Zverev in four sets in the last 16.

Murray's bid to win an elusive title at Melbourne Park has to wait another year after he suffered a stunning 7-5 5-7 6-2 6-4 defeat to the world number 50 on Sunday.

The three-time grand-slam champion - a runner-up on five occasions at the Australian Open - simply had no answer to Zverev's relentless serve-and-volley style as he followed title holder and world number two Novak Djokovic through the exit door in the opening week.

Younger brother Alexander Zverev almost pulled off an upset of his own against Rafael Nadal on Saturday before fatigue set in, but Mischa - without an ATP Tour single's title - went one step better than the 19-year-old German on Rod Laver Arena after competing in the fourth round of a major for the first time.

After more than three-and-a-half hours, Zverev will face either Roger Federer or Kei Nishikori in the quarter-finals.

Olympic gold medallist Murray looked in control early, taking a 3-1 lead, only for Zverev to rip a backhand winner down the line as he broke back immediately.

The Brit then fended off two break points and went on to claim a break of his own for a 5-3 advantage, but he was pegged back again by Zverev in the ninth game.

With the match back on serve, Zverev coolly broke for a 6-5 cushion - capitalising on Murray's struggling second serve - and he closed out the set in style with an ace.

Murray raced out of the blocks in the second set for a 2-0 lead, but just like the opener, he dropped off having threatened to pull clear.

After earning three break points in the third game, Zverev broke through, though Murray hit straight back as the pair exchanged breaks.

That trend continued as Murray - after wasting four break points in the ninth - eventually levelled the match.

Zverev, however, refused to be overawed, with his serve-and-volley game wreaking havoc, claiming the double break and adding insult to injury with a passing shot that ricocheted into Murray's face before he took a two-sets-to-one lead.

And the 29-year-old continued where he left off in the fourth set, dazzling with his net and approach play as he broke Murray in the opening game.

It was a break he never relinquished in clutch moments after three hours, 33 minutes on court as Murray failed to make it beyond the fourth round of the Australian Open for the first time since 2009.

STATISTICAL BREAKDOWN
Zverev bt Murray [1] 7-5 5-7 6-2 6-4

WINNERS/UNFORCED ERRORS  
Murray – 71/28
Zverev – 52/26

ACES 
Murray – 10
Zverev – 7

BREAK POINTS WON 
Murray – 5/13
Zverev – 8/17

FIRST SERVE PERCENTAGE 
Murray – 66
Zverev – 66

PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE 
Murray – 65/36
Zverev – 66/46

TOTAL POINTS 
Murray – 136
Zverev – 146