Forced to play catch-up after Thursday's seven-hour delay, golfers battled through wet and cold conditions at Riviera Country Club, with half the field playing over 18 holes.
Thomas and Scott reached 10-under before the horns sounded to stop play. The pair shot opening rounds of 66 earlier in the day.
Jordan Spieth concluded his Round 1 early Friday. He sits at 7-under and won't start his second round until Saturday.
Tiger Woods, who played alongside Thomas, shot a 1-under 70 in Round 1. He climbed to 3-under with an eagle on his 27th hole of the day before closing with back-to-back bogeys.
Round 2 will resume Saturday at 10:00 a.m. ET.