Updated

Brendon Todd birdied his final two holes Friday to take a two-stroke lead after two rounds at the Byron Nelson Championship.

The birdies at Nos. 17 and 18 wrapped up a 6-under 64 and put Todd alone atop the crowded leaderboard at 8-under 132. Among eight players at 6 under were Martin Kaymer, The Players Championship winner Sunday, and Paul Casey after his record back nine.

Casey was over par before matching the PGA Tour record for the best score on a back nine, an 8-under 27 with six birdies and an eagle. That was part of his 7-under 63 that was the low round of the day.

Also at 6 under were 2003 Masters champion Mike Weir, fellow Canadian Graham DeLaet, Morgan Hoffmann, Tim Herron, Charles Howell III and Marc Leishman.