Rafael Nadal survived a huge scare to reach the Australian Open semi-finals with an enthralling five-set win over Denis Shapovalov on Tuesday.

Nadal is two wins away from a record-breaking 21st grand slam title after enduring a four-hour epic to beat Shapovalov 6-3 6-4 4-6 3-6 6-3 on Rod Laver Arena.

A year after losing from two-sets-to-love up at the same stage to Stefanos Tsitsipas, there was almost a repeat for Nadal.

But, seemingly battling a stomach issue, the Spaniard remained alive in his bid to set the outright record for most grand slams won by a man, following a thrilling battle that lasted four hours, eight minutes.

The success saw Nadal – who will face either Matteo Berrettini or Gael Monfils in the last four – reach his 36th career grand slam semi-final and seventh at Melbourne Park, where he claimed the title in 2009.

Nadal landed the first blow with a break to love in the fourth game.

A superb forehand winner down the line got Nadal going before three wild forehands in a row from Shapovalov saw him fall 3-1 behind.

Shapovalov was unable to make any inroads against the Nadal serve, winning just five return points in a 39-minute opening set.

The Canadian was angry with chair umpire Carlos Bernardes' decision not to give Nadal a time violation between sets and the players unusually met at the net before the second game of the second set.

Nadal needed a tough hold during a 12-point sixth game and he capitalised in the next, an overhead securing the break after Shapovalov had sent a forehand well long at 30-30 to end a point he had been in complete control of.

Nadal closed out the set, but found trouble in the sixth game of the third as he faced break points for the first time after a double fault.

After saving both and holding serve, Nadal was broken at the key time – when serving to stay in the set – as Shapovalov delivered a backhand cross-court winner to extend the contest.

The momentum had well and truly swung and a double fault from Nadal saw Shapovalov break for 3-1 in the fourth set.

Approaching the three-hour mark, Nadal required a medical timeout, seemingly suggesting an issue with his stomach.

Shapovalov found himself in some trouble trying to level the match, but recovered from 15-40 to force a fifth set.

Nadal – who had been beaten from two-sets-to-love up just twice previously in his grand slam career – had to save a break point in the opening game of the decider, a volley winner to hold drawing huge cheers from the Rod Laver Arena crowd.

Instead, Shapovalov played a loose game, two wayward forehands, a double fault and a framed backhand giving Nadal a break and 2-0 lead.

Nadal, looking far more energetic, saved two break points in the third game before becoming more comfortable on serve on his way to the last four, Shapovalov smashing his racquet after match point.

DATA SLAM: Nadal overcomes major Melbourne hurdle … just

Nadal improved his record in grand slam quarter-finals to 36-9, but the last eight has often been a problem in Melbourne during his incredible career.

He is now 7-7 in Australian Open quarter-finals after surviving the Shapovalov battle, far worse than his record at the French Open (14-1), Wimbledon (7-0) and US Open (8-1).

WINNERS/UNFORCED ERRORS
Nadal – 41/28
Shapovalov – 53/51

ACES/DOUBLE FAULTS
Nadal – 8/11
Shapovalov – 20/5

BREAK POINTS WON
Nadal – 3/7
Shapovalov – 2/8