NEW YORK: Second seed Dominic Thiem edged a first-set tiebreak before turning up the heat to romp into the US Open quarter-finals with a resounding 7-6(4) 6-1 6-1 victory over Canadian youngster Felix Augur-Aliassime at Arthur Ashe Stadium on Monday (Sep 7).
Top seed Novak Djokovic's disqualification on Sunday for striking a line judge with a ball has left Thiem as one of the favourites and the Austrian gave a composed performance to reach the last eight in New York for the second time in his career.
He was helped in his quest for a maiden Grand Slam title by a below-par performance from the talented Augur-Aliassime, who beat Andy Murray in round two but was well off the pace against Thiem, making 51 unforced errors versus the second seed's 24.
After a cagey opening, Thiem drew first blood, breaking his 20-year-old opponent to take a 3-2 lead in the first set after a pair of unforced errors by Augur-Aliassime.
Thiem consolidated with a hold to love, but stumbled in the 10th game, opening with a double fault and offering two break points after a couple of loose backhands before surrendering his serve with another error to allow his opponent to draw level.
Augur-Aliassime started the tiebreak with an ace, but Thiem regained the initiative to open up a 3-1 lead and sealed the set after the Canadian's 24th unforced error.
"The first set was really important," Thiem said in an on-court interview. "I was really nervous before the match.
"I had a chance to serve for the first set, missed it pretty poorly but then the tiebreak was really good. I started to miss less and less."
The Austrian broke Augur-Aliassime's serve again at the start of the second set and did not look back, delivering an ominous statement of intent as he dominated the youngster and ran away with match.
"I've started to find that mix again, which I had last in Australia, I guess," added Thiem, who lost to Djokovic in the Australian Open final. "The perfect mix of offence and defence.
"I'm really not missing a lot, pulling a lot of returns back in play. It was my best match so far and I'm going to try to keep that form for the next one."
Thiem won 74 per cent of his first serve points and was near flawless at the net, while also sending down 22 winners as he wrapped up the contest in a shade over two hours.
Next up for the 26-year-old is a quarter-final clash with Australian youngster Alex de Minaur, who he has beaten in both of their previous meetings, including in the opening round at Flushing Meadows three years ago.