IRVING, Texas - Australian golfer Marc Leishman remained in second place on Friday at the halfway mark of the Byron Nelson Championship in Texas.
Brendon Todd birdied his final two holes to wrap up a six-under-par 64 and take a two-stroke lead for a two-round total of eight-under 132.
On a crowded leaderboard, Leishman is among eight players at six-under (134). With him are Martin Kaymer and Paul Casey after a record back nine.
Casey was over-par before matching the PGA Tour record for the best score on a back nine, an eight-under 27 with six birdies and an eagle. That was part of his seven-under 63 that was the low round of the day.
Todd, who is back on the PGA Tour after getting his card back through the Web.com Tour, moved to seven-under with a 12-foot birdie at the par-3 13th hole. But he gave that stroke back at the par-4 15th when he hit his first two shots into the rough and had his only bogey.
He took the lead after his six-foot birdie at the par-3 17th, where his tee shot rolled just past the hole. The last of his seven birdies, in a round when he needed only 22 putts, came after his approach inside 10 feet at 18.
Also at six-under were 2003 Masters champion Mike Weir (66), who hasn't had a top-25 finish since 2010 when he had an elbow injury, fellow Canadian Graham DeLaet (66), Morgan Hoffmann (66), Tim Herron (66) and Charles Howell III.
Kaymer had his second consecutive 67 and has been in the 60s for all six of his rounds at TPC Four Seasons.
Peter Hanson was leading after a first-round 65, but was eight strokes worse on Friday and dropped back to equal 25th at two-under.