Mark Williams remains on course to honour the late Doug Mountjoy and win his home Welsh Open, but he had to withstand a determined fightback from Tom Ford to reach the semi-finals.
Mountjoy passed away at the age of 78 of February 14, and Williams immediately made it his goal to win the event in the name of his fellow Welshman.
He made excellent progress to the last eight, but was given a severe examination by a player who said pre game that he was not happy with life on the table.
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Ronnie O’Sullivan lies in wait in the semi-finals, and it will be an intriguing match between two players who have six Welsh Open wins between them.
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Ford was in first in the opener, but missed a pink into the right middle and it proved costly as Williams pounced with a 70.
Ford came into the game in a negative frame of mind, telling Eurosport that he was not enjoying his snooker, and his mood would not have been improved by the events of the second frame.
He knocked in a couple of excellent long pots to get going and compiled a break of 60, only to miss a routine red into the bottom-left corner.
Ford got a further chance after being put in a devilish snooker by Williams which yielded 18 points in fouls, but missed a green with the rest and was punished by his opponent.
The third saw Williams get in first with a break of 67, but he was the one to miss with the frame at his mercy. Ford had a chance to counter, but left a red in the jaws which enabled Williams to open up a three-frame cushion.
For all his struggles, Ford had knocked in some excellent balls and his potting prowess enabled him to get a foothold in the match in the fourth frame.
It was a see-saw affair, with both players holding the advantage at different stages. Williams looked well set to take the frame, only to pot a black and screw the white into the right middle.
With only the colours remaining, Ford knocked in a superb brown and brilliant long blue to take the final frame before the interval.
Ford came out after the break with a renewed sense of purpose and produced the first one-visit frame of the match as a break of 92 cut the deficit to one frame.
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With Ford threatening a comeback, Williams produced the response of a three-time world champion with a break of 86 to move within one frame of the win.
Despite not looking overly happy, Ford did not throw in the towel. His long-pot success was an impressive 92%, and an excellent red enabled him to get in and cut the deficit to 4-3.
Ford twice fought back from two down with three to play earlier in the tournament, when beating Elliot Slessor and Kyren Wilson, and he took the match to a deciding frame when taking an eighth that both players had chances to secure.
Williams got in first in the decider, but ran out of position on 24 and handed the table to Ford.
Mistakes from the cue of Ford were rare after the interval, but he made one when it mattered in the final frame.
He over-screwed from yellow to red by about two feet and it proved fatal as after snookering himself, Ford left Williams an admittedly tough pot to the right middle which he rolled in and duly compiled a nerveless break of 48 to book his place in the last four.
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