Min Woo Lee has had his big lead trimmed as he fights doggedly for a maiden PGA Tour triumph at the drama-charged Houston Open. The in-form Lee entered the back nine with a three-shot final-round buffer as some of golf's biggest names hunted the Australian down. After starting the day four strokes in front, Lee must have felt the pressure of carrying his first 54-hole lead but it didn't show as he drained a series of clutch putts to keep his chasers at bay. With two birdies, including a brilliant bounce-back at the ninth after a controversial but crucial par save at No.8, Lee surged to 19 under for the tournament. Former US Open champion Gary Woodland was his closest pursuer at 16 under, with world No.1 Scottie Scheffler and the second-ranked Rory McIlroy lurking four shots behind in what shaped as a tense finish. After letting share of the halfway lead slip at this month's prestigious Players Championship, Lee is hoping to claim his first PGA Tour win after two runner-up finishes plus three victories on the European Tour, including the 2023 Australian PGA Championship. The richly talented 26-year-old's inevitable Sunday nerves would have settled somewhat when his final-round playing partner and closest chaser Alejandro Tosti dropped a shot at the opening hole to fall five behind. Even without draining either of two 12-foot birdie putts on his first two holes, Lee suddenly found himself five shots clear of seven chasers headed by Scheffler, Woodland and New Zealander Ryan Fox. He matched Scheffler's birdie at the third to maintain the margin before scrambling for an up-and-down par after finding trouble off the tee on No.4. From eight back starting the day, McIlroy roared into the mix with an eagle and four birdies in his first 10 holes to pull within three as Lee continued grinding out the pars. But Lee's experienced Irish caddy had to talk the social media superstar out of dicing with fire and attempting an audacious shot off his knees on the par-5 eighth hole. Struggling with his driver all round, the West Australian was fortunate to stay in bounds but still found his ball under a tree. After a lengthy deliberation, he wisely opted to take a two-club-length penalty drop and eventually saved par after a painstaking 33-minute drama. The ordeal prompted Tosti to complain to official officials, the Argentine frustrated about the amount of time for Lee took to decide on his second shot. Tosti's anguish would have been compounded when Lee struck his wedge shot from 87 yards to six feet and holed the putt, then stiffed his approach on the par-3 ninth to set up a priceless birdie to edge three shots clear.