Scottish Open: Mark Allen snatches 6-5 semi-final win over Daniel Wells
Northern Ireland's Mark Allen took the final four frames of the match to clinch a tense Scottish Open semi-final victory over Welshman Daniel Wells 6-5.
World number six Allen was woefully out of sorts as Wells, ranked 66th, moved 4-0 up by the interval in Glasgow.
Wells, 30, still looked in control at 5-2 but crucially fouled in the eighth as he touched the green with his shirt.
Allen punished the error with a break of 79 and a run of 106 was followed by a 129 clearance in the final frame.
The Northern Ireland man's final opponent with be either Judd Trump or Shaun Murphy, who meet in Saturday evening's all-English second semi-final.
Last week's beaten UK Championship finalist Allen could only manage a top break of 24 in the first four frames as he missed a succession of chances.
Neath native Wells, playing in his first ranking semi-final, fought back from requiring a snooker to win the second frame and continued to punish Allen's poor play as he moved 4-0 ahead, helped by a top break of 56.
However, Wells missed a chance to extend his lead in the next after getting out of position while leading 49-0 as Allen's run of 55 saw him open his account.
Allen won the next with a 59 break, but Wells looked to have struck a major psychological blow as he potted the final red and colours to snatch the seventh frame on the black.
Wells was in again early in the eighth but as he attempted to line up a pot on a red with the rest, he touched the green with his arm as Allen gleefully took the chance with his 79 break.
As the Welshman turned down a number of opportunities for pots, Allen's positive approach paid dividends in the closing three frames as his two centuries help seal his comeback win.
Sunday's final will see Allen aim for a second ranking tournament triumph this season following his International Championship success in China last month.