Chinese youngster Bu Yunchaokete claimed the biggest win of his tennis career after a straight-set victory over Andrey Rublev on home soil at the China Open on Monday.

The 22-year-old continued to make history in the event as he achieved his first career victory over a top 20 player, beating Lorenzo Musetti to reach the quarterfinals of an ATP 500 event for the first time, and winning some style points with a forehand winner down the line.

Buyunchaokete went on to take the opening set 7-5 and continued to go 5-3 up in the second.

Rublev narrowed the gap facing a break point at 5-4 down, but the home favorite didn't give the Russian the opportunity as he saved it with an overhead smash.

The Chinese sealed the win 7-5, 6-4 with an ace, achieving his first win over a top 10 player since turning professional. Bu is now just two matches away from claiming a first ATP Tour title, where he will face the top-seeded Jannik Sinner in the semifinal.

"I defeated a Top 20 player in the second round, and this time I beat a Top 10 player, so now I have reached the semifinals, and I know the level of my opponent will be like world number one or number two. Of course, I feel very excited, just like in this match, and it was really crazy that more than 10-thousand fans come to support me, so there was no excuse not to fight hard, and I quite enjoyed the match. I think the next match will be the same, because it is the National Day holiday, and many fans will come to watch the match. I really appreciate their support," Bu said.

Second seed Carlos Alcaraz of Spain defeated Russian Karen Khachanov in two sets.

After Alcaraz took the first set 7-5, he continued to dominate in the second, and went in front 3-2. The three-time Grand Slam winner closed things out 6-2, when Khachanov hit the ball into the net. 

Alcaraz will meet another Russian, Daniil Medvedev, in the semifinals.