IRVING, Texas (AP) - Louis Oosthuizen birdied four of the last five holes for a 6-under 64 and a share of the third-round lead with Brendon Todd on Saturday in the Byron Nelson Championship.
Oosthuizen had the low round of the day after recovering from bogeys on two of the first four holes. The 2010 British Open winner is will play in the final group Sunday during an extended stretch when he has had to deal with back and neck issues.
Todd had a 68, making 12 consecutive pars before holing a 4-foot birdie at No. 18 to match Oosthuizen at 10-under 200.
Oosthuizen was 2 under for the tournament and well off the pace after his bogey at No. 4, when he hit his second and third shots from the rough and then was in a greenside bunker. The South African blasted to about 10 feet and had to make that putt for bogey, then made three birdies in a row.
He made an 8-foot birdie putt at the par-3 fifth, and followed that with an approach to 6 feet at No. 6 and a two-putt from 58 feet at the par-5 seventh.
Mike Weir, James Hahn and Gary Woodland were a stroke back.
Weir, the 2003 Masters champion who hasn't a top-25 finish since 2010 when he had an elbow injury, shot 67 while missing some makeable putts down the stretch. Hahn's 65 included five birdies in a row on the back nine, and Woodland shot 66 with a double bogey at No. 7.
Morgan Hoffmann twice fell out of the lead after hitting drives left into the water and making double bogey, at Nos. 11 and 18. He finished with a 68 and was tied for sixth at 8 under with three-time major champion Padraig Harrington, Marc Leishman and Graham DeLaet.
Oosthuizen had to withdraw from last year's Nelson with a neck injury and missed extended time last season. He won at home in South Africa in January, but is still bothered by back soreness.
He was feeling pretty good after his best round on the PGA Tour this season. He hit his approach to 4 feet at No. 10, then converted three straight short birdie chances at Nos. 14-16 before a closing 4 1/2-footer at No. 18.
Hoffmann was at 10 under and alone in the lead when he hit his drive into the water to the left at the 320-yard 11th hole, with Weir was just ahead on the green.
Weir then sank a 2-foot birdie putt to get to 10 under, having gotten to that spot with an impressive approach when from the rough just beside a bunker. Hoffman then hit another drive after the penalty and wound up with a double bogey.
That was the fourth birdie in a row for Weir before a bogey at No. 12, even when he got a break after his wayward drive apparently ricocheted off a tree and settled in the rough with a clear shot to the green. Weir got that stroke right back when he made an 11-foot birdie at the par-3 13th.
But after blasting from a greenside bunker at No. 15 to inside 5 feet, his par chance slid by the hole to drop him back to 9 under. He then missed a birdie chance from about the same length when it lipped out at the par-5 16th.
Hoffmann was again 10 under after birdies at Nos. 15-16, but hit his drive at No. 18 into the water and then hit twice out of the same greenside bunker.