Rafael Nadal battled into the Australian Open quarter-finals with a hard-fought victory over a determined Diego Schwartzman on Sunday.
The world number one was below his best but came away a 6-3 6-7 (4-7) 6-3 6-3 winner on Rod Laver Arena after three hours and 51 minutes.
Nadal slowly built into the fourth-round clash with the diminutive Argentine 24th seed, yet he was perhaps fortunate to win the first set and lacked ruthlessness in the second.
However, the 16-time grand slam champion advanced to the last eight in Melbourne for a 10th time, with Croatian Marin Cilic awaiting him.
But the Spaniard will be eager for improvement heading into the second week, having dropped a set for the first time at this year's championship.
Schwartzman looked the more likely to break in the first set, but Nadal saved four break points before taking a 5-3 lead.
Just as Nadal appeared ready to take control, he gave up a break advantage three times during the second set.
That proved costly as Schwartzman won the final three points in the tie-break to level the match.
Nadal made fewer errors as the contest wore on, even with Schwartzman's speed on the baseline forcing him into finer margins.
He took the third set and broke in the third game of the fourth, having saved five break points for 1-1.
Schwartzman continued to fight, but Nadal closed out his victory with another break in the ninth game.
Nadal  bt Schwartzman  6-3 6-7 (4-7) 6-3 6-3
Nadal - 46/52
Schwartzman - 58/68
Nadal - 7/4
Schwartzman - 12/3
BREAK POINTS WON
Nadal - 7/18
Schwartzman - 3/18
FIRST SERVE PERCENTAGE
Nadal - 68
Schwartzman - 54
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Nadal - 63/61
Schwartzman - 67/44
Nadal - 155
Schwartzman - 138