US Open 2020: 'Flat' Dominic Thiem fights his way into last-16 at Marin Cilic's expense

New York: Second seed Dominic Thiem said he must raise his game if he is to win a first Grand Slam at the 2020 US Open after ousting Marin Cilic in four sets to move into the last 16 Saturday.The 27-year-old Austrian, the losing finalist in the Australian Open this year, battled to a 6-2, 6-2, 3-6, 6-3 victory in the late match at an empty Arthur Ashe stadium."I felt a little bit flat," said Thiem, explaining his labors in sets three and four. "It's normal, it's really late, (and) without the crowd," he added.Thiem said he had yet to play at 100 percent in the tournament."I still have to raise my level if I want to go deeper," he explained.The world number three will play 20-year-old Canadian hotshot Felix Auger-Aliassime for a place in the quarter-finals.The 15th seed blew away France's Corentin Moutet 6-1, 6-0, 6-4 in just one hour and 57 minutes, becoming the first player born in the 2000s to reached a Grand Slam fourth round."Dominic has been getting stronger and stronger year after year," said Auger-Aliassime."You feel like step by step he's been reaching later stages of these tournaments, really becoming like a power in the tennis world. For me, it would be a good matchup," he added.[caption id="attachment_8788911" align="alignnone" width="640"] Vasek Pospisil stunned eighth seed Roberto Bautista Agut during the third round. AP[/caption]Auger-Aliassime was joined in round four by 94th-ranked compatriot Vasek Pospisil, who shocked eighth-seeded Spaniard Roberto Bautista Agut, 7-5, 2-6, 4-6, 6-3, 6-2.Pospisil, 30, struck 70 winners to reach the last 16 at Flushing Meadows for the first time."I'm thrilled. I was playing great tennis all the way through," he said.With 12th seed Denis Shapovalov already through, the next round marks the first time three Canadian players have reached the second week of a Grand Slam at the same time.Pospisil will take on 21st seed Alex de Minaur for a place in the last eight after the Australian rallied from two-sets-to-one down to upset 11th-seeded Russian Karen Khachanov 6-4, 0-6, 4-6, 6-3, 6-1.The Aussie number one broke serve six times to set up the match with Pospisil, who he has beaten in two career ATP meetings."Definitely building some confidence, and hopefully I can keep this momentum going," de Minaur said.'Businesslike'Elsewhere, America's Frances Tiafoe obliterated Hungarian Marton Fucsovics 6-2, 6-3, 6-2 in 1h 44m to set up a last 16 showdown with Russian third seed Daniil Medvedev."It was definitely one of my best performances start to finish," said Tiafoe, the last remaining American in the men's singles."I wasn't trying to be too fancy. I just kind of got it done today. Very professional, very businesslike," added the 22-year-old.Italian sixth seed Matteo Berrettini and Russia's 10th seed Andrey Rublev both enjoyed easy three-set wins to set up a last-16 clash against each other.Rublev only gave up four games as he pulverised unseeded Italian Salvatore Caruso 6-0, 6-4, 6-0."It's going to be really tough. He's serving well. Forehand and backhand, they are great, like, weapons," Berrettini said of Rublev.Top seed and world number one Novak Djokovic is overwhelming favorite to win an 18th Grand Slam at the 2020 US Open.