Ormsby had a 5-under-par 67 and Vongvanij shot 69, leaving them at 7-under 137 after 36 holes.
A large portion of the field was still on the course when the second round was halted Friday because of darkness. A delay because of rain and fog Thursday pushed play back and many golfers had to finish the first round Friday.
Lightning caused the start of Friday's play to be pushed back an hour, meaning dozens of players were unable to finish the second round before it became too dark to play.
Still on the course were the five players tied for first after Thursday's play. In that group was Matthew Baldwin, who got in just six second-round holes Friday and is 4-under for the tournament.