Six-time Australian Open champion Roger Federer came from behind to reach the quarter-finals in Melbourne with victory over Marton Fucsovics.
The Swiss, 38, beat the Hungarian 4-6 6-1 6-2 6-2 and will play American Tennys Sandgren in the last eight.
After losing the first set, Federer breezed through the second and third, winning seven successive games.
He twice broke Fucsovics in the fourth set before serving out the win on his third match point.
Federer battled for more than four hours to see off John Millman in the third round and he looked unsure of the wind conditions on Rod Laver Arena.
However, the 20-time Grand Slam champion found his footing and showed some fine touches at the net in the final two sets to reach the quarters.
“The morning after the (Millman) match and this morning, I lay in bed and after an hour I was wondering how to get up,” Federer said.
“I’m sure I’m going to feel better every day that goes by.
“I had a good start to the second set and from then on it got a little bit easier.”