Milos Raonic dramatically got past Stan Wawrinka to advance to a second straight Australian Open quarter-final on Monday.
The big-serving Canadian steadied in the deciding set to claim a 6-4 6-3 5-7 4-6 6-3 victory on Rod Laver Arena.
Raonic, the 13th seed, started the year by winning the Brisbane International and he has carried those performances to Melbourne Park.
Wawrinka, who had been suffering from the flu in the first week, appeared to lack energy early on before finally finding some life.
But the two-time grand slam winner and 2014 champion was left to rue his poor start as Raonic completed his first win over Wawrinka in three hours, 44 minutes.
As Raonic took his chances, fourth seed Wawrinka's forehand in particular fell apart, that side committing 19 of his 31 unforced errors.
Raonic came forward when he had the chance and won 54 of 83 points at the net as he set up a last-eight meeting with Frenchman Gael Monfils.
It had all looked set to be much easier when a faltering Wawrinka allowed him to take complete control of the match.
Neither player had faced a break point until Wawrinka got himself into a hole in the ninth game, a double fault and two forehand errors gifting Raonic a 5-4 lead he would capitalise on.
For just the second time this tournament, Raonic was broken as he fell behind 2-0 in the second set - but Wawrinka handed that advantage and more straight back.
When the Swiss ripped a forehand into the net, he had lost three straight games and suddenly found himself a set and a break down before Raonic saw out the second with relative ease.
It was the Raonic forehand which turned loose late in the third set as two errors saw Wawrinka break for 6-5 on his way to getting back into the match.
Wawrinka, with his energy levels higher, capitalised on Raonic's missed chances in the fourth, breaking in the fifth game on his way to levelling the contest.
The match took another turn in the sixth game of the fifth as a Wawrinka forehand pass went long on break point to see Raonic take a 4-2 lead, and the latter was forced to serve it out - which he did with conviction.
Raonic  bt Wawrinka  6-4 6-3 5-7 4-6 6-3
Raonic - 24
Wawrinka - 9
Raonic - 82/53
Wawrinka - 52/31
BREAK POINTS WON
Raonic - 5/15
Wawrinka - 3/8
FIRST SERVE PERCENTAGE
Raonic - 68
Wawrinka - 58
PERCENTAGE OF POINTS WON ON FIRST/SECOND SERVE
Raonic - 79/48
Wawrinka - 71/51
Raonic - 167
Wawrinka - 153