Chinese youngster Si Jiahui took the lead 5-3 in an interesting first session of his World Championship semi-final match with Luca Brecel.
The 20-year-old, who came through qualifying at the Crucible to make those final stages, lost the first frame, but produced back-to-back clearances of 125, 102 and 97 to punish Brecel for near-show errors without fault. of breaking construction.
But the Belgian, who beat seven-time champion Ronnie O’Sullivan in the last eight, clawed his way back to 4-3 down before succumbing in a thrilling final to the final frame of the evening.
At the start of the opening frame, Brecel took advantage of a scary puck when he hooked the pinky in the jaws and saw the ball run the length of the table down the cushion before falling in.
He reached 50 before losing the blue, although Si, the youngest semi-finalist in the tournament since O’Sullivan in 1996, was unable to prevent him from progressing.
However, the youngster announced himself in style in the second, sinking a tough red to go in before compiling an imperial break of 125, and repeated the feat to take a 2-1 lead when, after the Belgians lost the yellow at 33-. 0, he cleared the table again in visit 102 to complete the back-to-back centuries.
Si eased himself into a 3-1 lead at the intermission in the middle of the session after a hand-to-hand fight in the fourth frame when both players missed two difficult scores to the middle pockets before gaining 103-29 courtesy of a 97 break.
The world number 80 went down briefly, asking for a regulation red as he performed on the right with the tip ball in an attempt to develop the pack after Brecel again erred, but eventually tied an untidy fifth frame 103 -3.
The first significant error that Si made in the next came when, 53 points into another break that looked decisive, he jawed the black to let his opponent to the table, and his break of 72 stopped the decay.
After taking advantage of a mistake, Brecel gave it back almost immediately, following up a good long red with a careless blue, but the Chinese player was just as profligate, leaving himself unable to seeing color as he tries to develop the pack in seven attempts. who hit the designated brown.
A further 12 points came from the second snooker and three more misses, leaving the 28-year-old 38-33 ahead, and he eventually pulled back to within one frame of his opponent with a visit of 69 .
The final frame of the session did not end with a lasting safety exchange, but it was Brecel who made the first move with a 33 break before inexplicably losing the pink, although Si lost at 43-34.
His opponent’s pink reached to the top pocket which would have leveled the game at 4-4 and saw it roll agonizingly over the middle for the young man to go up two.
Mark Allen finished the opening stanza of the other semi-final against Mark Selby on a roll, winning the final three frames for a 5-3 overnight lead.
A 123 clearance gave Selby a great start but uncharacteristic errors in the safety battles in the next two frames allowed his Northern Ireland opponents to take control with breaks of 63 and 66.
Selby lost his spot in the fourth frame but still went into the mid-session interval level at 2-2 as it was Allen’s turn to flush his lines in a tactical exchange.
A break of 68 sent Selby into the lead in an exhausting and flowing session and although Allen was level, there was a hint of controversy when replays showed he was grazing the red he was moving to make a tough pot.
The referee didn’t see the lie and Allen didn’t admit it either – with players as scrupulous about pointing out any wrongdoing at the table – the left-hander, who won three of the ranking occasions this season, he had nothing to do with what he had done.
Selby later visited the table but his rival’s break of 64 left him well ahead and Allen quickly wrapped up the frame. Allen then finished the session with breaks of 60 and 78 to seize the initiative.