Jon Rahm will take a four-stroke lead into the final round of the Memorial Tournament as he bids to replace Rory McIlroy as world No 1. The Spaniard will top the Official World Golf Ranking for the first time if he wins and McIlroy, who finished the day 10 shots back in a share of 12th, finishes worse than a two-way tie for second. Even a runner-up finish could see Rahm become world No 1, but, after a commanding third round 68 in Ohio, the 25-year-old will hope not to have to concern himself with those permutations. A birdie from five feet at the seventh was followed by a bogey on the next after Rahm tangled with a bunker in an uneventful front nine. However, in tough conditions at Muirfield Village, Rahm reeled off four successive birdies from the 13th to take control of the tournament. “It’s a good job done today,” Rahm told Sky Sports Golf. “It was not easy out there today. That front nine was hard. I kind of got things rolling, I started playing beautiful golf from nine onwards and gave myself chances and kind of took off.” On 12 under par he leads by four from Americans Ryan Palmer and Tony Finau – the latter putting a serious dent in his chances of a second PGA Tour title when he lost his cool on the back nine. Having double-bogeyed the 12th, Finau took the ill-advised decision to attempt to drive the green on the 14th only to find water en route to a bogey, before blindsiding himself on the 17th trying to clear the dog-leg with his tee shot and running up another double bogey. That saw him match Palmer’s 73, with England’s Danny Willett fourth on six under following a round of 70. McIlroy carded a level-par 72 to remain two under, with Tiger Woods going one better to improve to two over for the tournament.