Hoey, of Northern Ireland, and Atwal, of India, shot 8-under-par 62s.
Englishman Matthew Cort and South African Chris Williams trailed the two clubhouse leaders by a stroke at 63 and five others were at 64.
Lightning delayed play for more than two hours and the round was suspended with 57 golfers on the course. They will complete the first round Friday.
The tournament is part of the European Tour international schedule.