Coleman Wong's fairytale US Open campaign came to a halt in the third round on Saturday as the Hong Kong, China star exited after a five-set thriller against Russian 15th seed Andrey Rublev.

Wong -- the first player from Hong Kong ever to win a Grand Slam singles match in the Open era -- bowed out in a 2-6, 6-4, 6-3, 4-6, 6-3 defeat at Flushing Meadows.

The experienced Rublev was pushed all the way by the 21-year-old, who trains at Rafael Nadal's tennis academy in Spain, and who had fought his way into the main draw via the qualifiers.

Wong, ranked 173rd in the world, delighted a packed crowd with some superb shots, his signature disguised drop shot repeatedly leaving Rublev scrambling at the net.

"Tough, tough match," a relieved Rublev said after his more than three-hour battle.

"He was playing with no fear, really aggressive. I didn't start well and he was all over me. I had to fight for every ball to turn around the match."

Rublev revealed he had been expecting a tough challenge after practicing against Wong in Cincinnati recently.

"He destroyed me on the practice court and he beat me," he said. "That gave him the confidence today to play super-good."

Rublev will now face either third seed Alexander Zverev or Canada's Felix Auger-Aliassime in the last 16 on Monday as he attempts to reach the quarter-finals for the fifth time. (AFP)