Jordan Spieth is one stroke behind a trio of leaders after weather delays kept the world number two to a six-under-par 64 in the first round of the AT&T Byron Nelson.
Competing for just the second time since his spectacular collapse at last month's Masters having missed the cut at The Players Championship, Spieth only dropped one shot as rain and thunder delayed play for over an hour, with no less than 25 players unable to complete their rounds.
Sergio Garcia, Danny Lee and Johnson Wagner shared the lead before the round was suspended due to darkness on Thursday.
Garcia was the first of the leaders to complete his round after starting on the back nine, posting five birdies and an eagle in a flawless display.
The Spaniard managed just one birdie from his first nine holes but was superb following the turn as he made four birdies and an eagle.
Lee joined him late in the day, holing seven birdies without dropping a shot.
Wagner was the last of the leaders to finish and was level with Garcia and Lee with three holes to play and made par on each of them to retain his share of the lead.
Spieth did not drop a shot on the front nine and found another four birdies after the turn with just the one bogey at the 13th hole for the round.
Dustin Johnson and Freddie Jacobson are also level at six under, along with Tom Hoge, who was through 14 holes at the close of play.
Defending champion Steven Bowditch, meanwhile, finished his round but is already some way off the pace, sitting five shots off the pace alongside the likes of Ernie Els and Zach Johnson.