Jordan Thompson has earned the biggest pay day and biggest opportunity of his career after powering into the fourth round of the US Open in New York.

The Australian Davis Cup star outclassed Mikhail Kukushkin 7-5 6-4 6-1 on Saturday to reach the second week of a grand slam for the first time.

Thompson’s victory earned the 26-year-old Sydneysider at least a $US250,000 cheque and a last-16 crack at either Greek fourth seed Stefanos Tsitsipas or Croatian Borna Coric on Monday.

In another clean serving display, Thompson struck 10 aces, only two double-faults, landed 65 per cent of his first deliveries and was broken just twice.

Closing in on a return to the world’s top 50, he mixed 26 winners with 24 unforced errors compared to the Kazakh’s 44, which mostly came from the baseline while trying to stay in rallies with the Australian.

In progressing to the round of 16 for the loss of only two sets, Thompson’s run betters his third-round showing at last year’s French Open, which bodes well ahead of next month’s clay court slam in Paris.

Australian No.1 Alex de Minaur has the chance to join Thompson in the fourth round on Sunday when he plays Russian 11th seed Karen Khachanov.

Elsewhere, Denis Shapovalov won the battle of North American young guns by grinding out a 3-6 6-3 4-6 7-6 (7-5) 6-2 win over Taylor Fritz to move into the US Open fourth round.

The match played out exactly as one would expect from two of tennis’s rising talents with the Canadian Shapovalov and American Fritz engaged in a seesaw tussle.

The big-serving Fritz had a chance to serve out the match at 5-3 in the fourth but Shapovalov grabbed the break he needed to drag the set to a tie-break which he won.

In the decisive fifth set it was the Canadian’s serve that made an impact, Shapovalov laying down seven aces to just one from Fritz.

“I was struggling serving because he was putting his racket on everything and he was playing so solid,” said Shapovalov, who has taken the long route to the last 16 with his opening two matches going four sets.

Next up for Shapovalov is Belgium seventh seed David Goffin who was a 6-1 7-6 (7-5) 6-4 winner over Serbia’s Filip Krajinovic.

In the women’s draw, former champion Naomi Osaka survived a third-round scare before grinding out a 6-3 6-7 (4-7) 6-2 victory over fearless Ukrainian teenager Marta Kostyuk to reach the last 16 of the US Open.

The Japanese fourth seed initially looked like she would enjoy a routine day on the court but was forced to dig deep to secure victory after two hours and 33 minutes against an 18-year-old making her US Open main draw debut.

“She didn’t back down from me or from, like, the speed of my ball, which for someone that young is kind of amazing, because I feel like, you know, the first set went that way, and then she could have faded in the second set,” said Osaka.

The two-times grand slam champion Osaka also said her left leg, which was heavily taped following the hamstring injury that forced her to withdraw from the final of a tune-up event last week, was still not 100 per cent.

After Osaka had breezed through the first set, a match filled with shifts in momentum suddenly turned in Kostyuk’s favour as she broke her opponent for the first time to pull ahead 4-3.

Kostyuk consolidated the break but dropped the next three games and had to hold serve to force the tiebreak.

She dropped the first two points but won seven of the next nine to close out the set, leaving Osaka to fling her racquet down in frustration.

“Everything was going really well for her during the tiebreak,” said Osaka. “She came to the net, and I hit it as hard as I could towards her, and she made it, and I was just, like, ‘whoa, this is unbelievable’.”

After Kostyuk went ahead 2-1 in the final set, the Ukrainian had her right ankle taped for the second time in the match.

Osaka then leaned on her experience, digging deep to save five break points in a 14-point game to draw level and from there won 16 of the next 19 points to close out the victory.

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Former world No.1 Angelique Kerber advanced to the last 16 with a 6-3 6-4 victory over 20-year-old American Ann Li.

Kerber, a three-time grand slam champion who won the title at Flushing Meadows in 2016, converted four break points while Li, who is ranked 128 in the world, was let down by 28 unforced errors.

Croatian eighth seed Petra Martic survived another sloppy display to see off grand slam newcomer Varvara Gracheva 6-3 6-3.

Martic was again often her own worst enemy, allowing her 20-year-old Russian opponent to stay in the contest.

American teenager Caty McNally raced past 21st-seeded Russian Ekaterina Alexandrova in a final set tiebreak to win 4-6 6-3 7-6 (7-2) in a second round match.

-agencies