Boo gives Jordan a fright but Spieth still top dog in Cromwell
Jordan Spieth resisted a spirited challenge from his fellow American Boo Weekley to preserve his one-shot lead in the Travelers Championship in Cromwell, Connecticut.
The former world number one has been the clubhouse leader since Thursday but needed a birdie on the 18th hole of his third round to pull a stroke clear of Weekley, who signed for a five-under 65.
England's Paul Casey will be in title contention on the final day after climbing into a share of fourth place with CT Pan and David Lingmerth following a 66 that contained five birdies and a bogey.
Irishman Padraig Harrington is five behind Spieth, the 2015 Masters winner, after shooting five bogeys in a one-over 71 that leaves him four under par.
Northern Ireland's Rory McIlroy - like Spieth making his tournament debut here - is 12 strokes off the lead and all but out of the race after following up Friday's poor 73 with an even-par 70.
Also suffering frustration was Charley Hoffman, who at one point took over at the top with four birdies across the front nine. On his way back in, however, he at one point shot 5-5-5 to drift away to a 68.
Spieth, 23, will be joined in the final pairing by Weekley after the Floridian found birdies on the 11th, 13th, 15th, 17th and then 18th holes.
Weekley, 43, said of his young opponent: "Jordan's a good dude. He's one of the most humble kids out here that play with us right now. Day in and day out, he's one of the most humble kids.
"My hat is off to him, and for who he is as a person."
Spieth, who is chasing his 10th PGA Tour title, replied on ESPN.co.uk: "I hope I'm having as much fun each day as Boo's having. I mean, he lives it up. It's fun to be around Boo.
"He's always very nice to everybody he sees. He's a guy everybody very much respects and really likes being around, and that's fun."