In a thrilling start to their World Championship semi-final, Si Jiahui took a 5-3 lead against Luca Brecel.

Brecel won the first frame with a break of 50, but Si quickly took control with two century clearances and a run of 97 as he won four frames in a row.

Brecel of Belgium responded with runs of 72 and 69, but China’s Si snatched the final frame on the black.

At 19:00 BST, four-time world champion Mark Selby will face Mark Allen in the last four.

Si wasn’t even on the professional circuit a year ago, and as a rookie, he had to win three qualifying matches to get to the Crucible, where he played 113 frames to Brecel’s 66.

Although Welshman Terry Griffiths won it as an unranked qualifier at the first try in 1979, the world number 80 is also the lowest ranked player to ever reach this level of the competition.

Despite only winning his last-four berth in a dramatic final-frame showdown against Scotland’s Anthony McGill late on Wednesday evening, the 20-year-old made a formidable start, displaying no signs of anxiety or exhaustion.

Si set to work after watching Brecel rip through the first frame, producing three brilliantly polished breaks of 125, 102, and 97 before demonstrating his already strong match-play to go 4-1 up.

Brecel, who infuriated his followers by failing to capitalize on multiple early chances to flip those frames in his favor, recovered admirably and appeared prepared to draw even, but he failed to knock in a tricky long pink after a stunning pot on the blue, letting his opponent to clean up.