Second seed Rafael Nadal ground down German Philipp Kohlschreiber to come through a testing clash 7-5 6-3 4-6 6-2 in the Australian Open second round on Thursday.
Nadal was forced to work extremely hard by the 23-year-old world number 61 in a pulsating night match at Rod Laver Arena, finally sealing victory after three and a half hours at 0130 local time.
"I feel very good, he was a very tough player and was returning very aggressively," Nadal told the crowd after receiving a standing ovation.
"But finally I won the match. This tough match for me was very important as it was a very good test."
Nadal, seeking his first Australian Open title and third grand slam, made an early break in the first set but Kohlschreiber slugged it out toe to toe with the Spaniard, fighting back to 5-5 and earning a break point to lead 6-5.
Nadal held firm, however, to hold his serve and after leading the next game 40-0 he clinched the first set on his third break point when Kohlschreiber netted a forehand to end a long baseline rally.
Nadal took control to win the second set but Kohlschreiber dug in, using his top-spin groundstrokes and devastating forehand to break the Spaniard in the third set and move 4-2 ahead.
Four successive games then went against serve, Kohlschreiber breaking the 20-year-old to love to clinch the set.
The trend continued at the start of the fourth set as Nadal came through after four deuces to take the early lead and he consolidated his advantage by finally holding serve.
Nadal, sensing victory, moved 4-0 ahead but Kohlschreiber still refused to lie down, clawing back two games before the world number two served for the match at 5-2.
The Spaniard created two match points and, after Kohlschreiber saved the first with another pinpoint crosscourt drive, Nadal forced the German to net a forehand to hand him victory.
Nadal will play Switzerland's Stanislas Wawrinka, the number 31 seed, in the third round.