Bill Haas carded a 5-under 67 on Friday to grab a 3-stroke lead at the Memorial Tournament before play was suspended for darkness.
The second round was briefly suspended for 22 minutes early in the second round due to the threat of a thunderstorm, and then later delayed for nearly an hour and a half for rain before the horn sounded for a third time to halt play for good.
Haas finished 36 holes at Muirfield Village Golf Club at 9-under-par 135.
"I'm very happy to shoot two good scores here," said Haas, who shot 68 on Thursday. "Those are probably my two best rounds here ever, so to do them back-to-back in very tough conditions I'm very pleased."
Matt Kuchar also finished his round and posted a 2-under 70 to sit in second place at minus-6.
He is joined there by Bubba Watson, Kyle Stanley and first-round leader Charl Schwartzel, who were all in the midst of the second rounds when play was suspended.
Haas started to make his run up the leaderboard with a 12-foot birdie putt at the fourth.
He followed that by chipping in for an eagle from a greenside bunker at the fifth, and then rolled in a 17-foot birdie effort at the sixth to move to 8- under.
After parring the next four holes, he recovered from an errant drive at the 11th to pick up another birdie, but 2-putted for bogey from six feet out at the 12th to fall back to minus-8.
He bounced back by starting back-to-back birdies at the 14th and 15th with a 21-foot putt, but just missed a 12-foot par putt at the last to close with a bogey, grabbing the clubhouse lead at 9-under.
"I really played nice, but then I did hit a few errant shots and when I did, I got away with them or made a nice par save. I would have liked to not bogey the 18th," Haas said.
Kuchar started on the back nine and opened with four straight pars before stumbling to a bogey at the 14th.
But he bounced back with a 4-foot birdie putt at the 15th and closed his outward nine with a 16-foot birdie effort at the 18th to make the turn at 5- under for the tournament.
He later capped back-to-back birdies at the third and fourth with a 21-foot birdie putt to pull within two strokes of the lead, but slipped to a bogey at the ninth to fall three shots off the pace.
"A bummer to walk off with a bogey, but it was nice golf today," said Kuchar. "I'm very pleased. My game's been good for a while now and I had two good rounds here. I'm looking forward to the weekend."
Watson was on a roll with six birdies around a bogey through 14 holes before play was suspended, while Stanley was playing steady with 10 pars, two birdies and a bogey over 13 holes to remain near the top of the leaderboard.
Schwartzel, however, countered three birdies with a double bogey and a pair of bogeys through 15 holes to drop out of the lead.
NOTES: The second round will resume at 7:30 a.m. (ET) Saturday. The third round will follow at around 9:30 a.m. with the players grouped in threesomes off split tees ... 42 players will need to finish their second rounds on Saturday ... Haas has recorded back-to-back rounds in the 60s at the Memorial for the first time in 26 career rounds ... Kuchar has not missed a cut this season ... Defending champion Tiger Woods carded a 2-over 74 in his second round and currently sits in a tie for 46th at 1-over-par 145.