Jannik Sinner has revealed the reason why he was seen vomiting into a bin during his quarter-final clash with Grigor Dimitrov at the ATP China Open.

The sixth seed moved past a three-set battle with Dan Evans and achieved a straight-sets victory against Yoshihito Nishioka to set up the clash with the World No. 19 Dimitrov.

Prior to the start of the ATP 500 tournament, the Italian player admitted that he was feeling sick upon his arrival in Beijing. While he was noticeably unwell in his clash with Evans, he seemed better by the time he ousted Nishioka 6-2, 6-0 in the Round of 16. However, as his match against Dimitrov went to a decider, the Italian was seen vomiting into a trash can.

The event occurred mid-way through the third set. Sinner had won the opener 6-4 before Dimitrov fought back to win the second 6-3. However, despite his evident sickness, the 22-year-old was able to secure the decider 6-2 and book a spot in the semi-final where he will face top seed Carlos Alcaraz.

After the match, Sinner revealed that the vomiting was not related to the illness he felt at the start of the tournament and that instead it was likely to be food poisoning.

"At one point I vomited, I probably ate something that made me sick," he said.

The World No. 7 will need to be in good health if he wants to stand a chance against the two-time Grand Slam champion Alcaraz. Their head-to-head is currently level at 3-3, with Sinner having won their most recent encounter in the semi-final of the Miami Open earlier this year.

However, Alcaraz leads their head-to-head on outdoor hard courts 2-1 and the Spaniard has been looking very much on form at the tournament in Beijing so far. He has swept past all of his opponents in straight sets, including seventh seed Casper Ruud who he defeated 6-4, 6-2 to set up the clash with Sinner.