June 24 (Reuters) - Jordan Spieth ended an up-and-down round on a high note, rolling in a 20-foot birdie putt at the last on Saturday to carry a one-stroke lead into the final round of the Travelers Championship at River Highlands in Connecticut.
Spieth, who has led since the opening round in a campaign for his first win since the AT&T Pebble Beach tournament in February, had three birdies over his last four holes for a four-under 66 to squeeze ahead of fellow American Boo Weekley.
The closing charge by Spieth followed back-to-back bogeys from the 13th and put him at 12-under-par 198, while Weekley made five birdies in a bogey-free back nine including the last two holes to shoot 65 for an 11-under total.
Three shots off the pace was American Daniel Berger (66), with C.T. Pan of Taiwan, who fired a 64 for the low round on a breezy day, Sweden's David Lingmerth (65) and Briton Paul Casey (66) another stroke back.
World number six Spieth, who has struggled of late to regain his top form, confidently poured in his right-to-left breaker on the last green with his sights set on notching a 10th PGA Tour title one month from celebrating his 24th birthday.
The 43-year-old Weekley, who has slipped to 390th in the world rankings, is gunning for his fourth tour title and first since winning at Colonial in 2013.
World number three Rory McIlroy, frustrated by his recent putting form, auditioned five different putters before Saturday's third round before choosing a half mallet styled flat stick.
It did not make a world of difference for the Northern Irishman, who shot 70 for an even-par 210 total that was one stroke inside the cut for Sunday's final round.
Reporting by Larry Fine in New York; Editing by Ian Ransom