Kuchar had a 1-under 69 that included some near misses and two nice par-savers to close his round to get to 11-under 199. Graham DeLaet, Boo Weekley, Chris Stroud and Matt Every were tied for second.
When the second round was suspended Friday night because of an approaching storm, Kuchar had just hit his tee shot at the par-3 16th. He resumed there at 7:13 a.m. Saturday with a two-putt from about 40 feet. That was part of three quick pars to keep his one-stroke lead after two rounds, and he then played in the final group that finished just after 5 p.m.
After his go-ahead stroke in the third round at No. 16 he had fallen behind by two strokes during the round Kuchar's approach shot at the 379-yard 17th landed in a greenside bunker and he blasted from there to 13 feet and saved par. At the 414-yard 18th, Kuchar hooked his tee shot into the left rough and found tall grass near the green with his second shot before pitching to 3 feet.
Weekly and Every shot 66. Stroud had a 67, and DeLaet, playing with Kuchar, had three back-nine bogeys before a birdie at No. 18 for a 69.
Ranked No. 13 in the world the highest in the field Kuchar started the third round with a birdie at the easy par-5 first hole. At the 458-yard third, his 8-foot birdie attempt rolled over the cup without falling, ending his streak of 34 consecutive holed putts under 10 feet this week at Hogan's Alley.
Kuchar missed another short one, a 5-foot par putt after blasting out of a greenside bunker at the seventh hole. He then missed the green on at the par-3 eighth and bogeyed again, putting him 9 under and two strokes behind DeLaet, the 31-year-old Canadian looking for his first PGA Tour victory.
DeLeat was at 12 under after matching Kuchar with a birdie at the par-5 11th, then bogeyed Nos. 13, 14 and 17.
Kuchar won the WGC-Accenture Match Play in February, and will try Sunday to join Tiger Woods as the only multiple winners on the PGA Tour this season. Kuchar is a five-time winner, but never has won twice in the same season.
There could be a lot of competition in the final round at Colonial, where 12 players are within three strokes of the lead. That dozen includes defending champion Zach Johnson, who also won in 2010, at 8 under.
Johnson shot 68, when his first bogey in 37 holes came at the 16th after he missed the green with his tee shot. Johnson has been under par in 18 of his last 19 rounds at Hogan's Alley, the lone exception his closing 72 last year that included a two-stroke penalty. Five-time winner Ben Hogan is the only player to win Colonial more than twice.
Weekley, who has won twice but not since 2008, got to 10 under during his second round Friday when he made consecutive birdies after making his turn. But he had a late four-hole stretch with a double bogey and two bogeys. He was back at 10 under Saturday with consecutive birdies at Nos. 11 and 12, and was still there after an up-and-down finish.
After missing the fairway with his tee shot and the green with his approach at the 451-yard 14th for a bogey, Weekley got that right back with a 6-foot birdie at No. 15. He missed a 5-foot par chance at No. 16, but finished with a birdie after his approach inside 3 feet at the closing hole.