Harold dreams of emulating O’Sullivan
Despite two century breaks Harold defeated Australian Quinten Hann 6-3 but only after a three-hour battle.
Outspoken Hann described his Stoke rival as "probably the most negative player I know".
Harold dismissed the claim but admitted: "I would love to play like Ronnie and if someone can give me his inspiration or whatever it is he's got then I would take it.
"Quinten can say I play slow but he also took his time as well.
Harold, who defeated Ken Doherty and Stephen Maguire to qualify for his first quarter-final in nearly 12 months, made the perfect start.
Breaks of 41, 67 and 103 gave the Potteries professional a 3-0 lead.
Hann was desperate to convert his sixth quarter into a first semi-final.
He rallied to pull two frames back with superb potting runs of 66 and 93 to trail just 3-2.
Harold edged a scrappy 28-minute sixth frame and then put himself in control by going 5-2 clear.
After Hann led 46-0 in frame eight Harold had a superb opportunity to reach his first ranking tournament semi-final since the 2000 Grand Prix at Preston.
Instead, he 'twitched' badly on the final red into a middle pocket and Hann cleared with 23 to keep himself in contention.
Harold then missed again at the start of frame nine but a kick on a red cost Hann his chance to exert more pressure on the world number 21.
And to his credit 36-year-old Harold, a 250-1 pre-tournament outsider, held his nerve superbly to finish off with 117.
