Ding Junhui gained control of his Betfred.com World Championship semi-final against Judd Trump as he won six out of eight frames in the second session this afternoon.
Sheffield-based Chinese cueman Ding had not gone beyond the second round in four previous Crucible campaigns but now has every chance of reaching his first final.
The 24-year-old took advantage of Trump's first poor session of the tournament to move from 5-3 behind to 9-7 ahead. He actually won five frames in a row from 7-4 down as 21-year-old Trump's form deserted him.
Trump had warned he might find it "a little bit daunting" if he fell behind, having made all the running in his one-sided wins over Martin Gould and Graeme Dott, which followed an opening-round win over last year's champion Neil Robertson.
The challenge he faces when he and Ding return at 7pm this evening is to ensure he remains in a position from which he can win the match tomorrow.
Ding made a rapid 91 break to take the opening frame of the morning but Trump punched in key balls to take the next before a huge slice of luck in frame 11 helped him open up a 7-4 lead. Playing an intended safety by sending the white down from baulk off the top cushion and back to edge off a red, he caught the red full, knocking it half a table's length into the yellow pocket.
Trump, the 21-year-old qualifier from Bristol, smashed a red off the table at the start of the next frame and Ding took advantage of his opponent's misses to move back to 7-5, and then returned after the interval with a run of 75 to cut Trump's lead to a single frame.
The flukes continued to favour Trump, but he was missing straightforward chances, the sort from which he was making frame-clinching breaks earlier in the tournament.
He looked like taking frame 14 to go 8-6 ahead, but after a lucky blue he added the pink and then ran to an awkward position on the black.
Trump attempted a difficult cut to the middle pocket which gently flicked the near knuckle and ran past. That in itself did not present Ding with a potting chance, but Trump soon left him a medium-range shot to win the frame, and in went the black.
Ding had a 60 break in that frame, and he continued to punish errors from Trump to open up his end-of-session lead.