By Ian Ransom
MELBOURNE (Reuters) - Stan Wawrinka's hopes of a second Australian Open title were delivered a huge boost on Sunday as he fended off Andreas Seppi 7-6(2) 7-6(4) 7-6(4) to reach the quarter-finals only minutes after top seed Andy Murray crashed out of the tournament.
Fourth seed Wawrinka now finds himself the highest ranked player in the top half of the draw and with the credentials to go all the way to emulate his 2014 championship.
The hard-working Swiss faces a tough match against former finalist Jo-Wilfried Tsonga for a place in the semi-finals where Murray can no longer be an opponent after the Briton's stunning upset by world number 50 Mischa Zverev earlier on Sunday.
Three-times grand slam champion Wawrinka has done it tough in the first week, surviving a five-set marathon in the first round and another four-set grind to reach the fourth round.
So he was thrilled to escape in three sets over Italian Seppi, having fought back from a break down to take the last into another tiebreak.
"Yeah, I think this match was the best match of the tournament so far, that's for sure," Wawrinka told reporters.
"Again, I'm not really worried about trying to improve every match, trying to play better or not.
"I know that my level is there, that physically I'm feeling good. So most important is to win, to still be in the tournament."
Showcasing the composure that has helped Wawrinka win all three of his grand slam finals, the Swiss lifted a gear in each of the three tie-breaks and his fearsome backhand was on fire as he closed out the match with a 53rd winner.
A searing backhand return down the line sealed the deal, booking a fourth quarter-final at Melbourne Park for the no-frills 31-year-old.
Never renowned for lively post-match interviews on the court, Wawrinka greeted news of Murray's elimination as if he had been informed that the sky was blue.
"Nothing," he said bluntly when asked for a reaction.
"It's a big surprise," he told reporters later when pushed.
"It shows that it's not as easy as we think, or when we see the draw, to just win, keep winning all the time."
With second seed and last year's winner Novak Djokovic dumped in the second round, only third seed Milos Raonic is higher-ranked than Wawrinka but the big-serving Canadian has yet to win a grand slam.
"I don't know why I should feel more pressure," said Wawrinka.
"I'm just in a quarter-final. Again, it's a big surprise that they are not in the draw anymore, but my next match is the quarter-final.
"I just think it's an interesting tournament."
(Editing by Sudipto Ganguly)