France's Victor Perez carded a second consecutive round of five-under-par 65 to take a one-shot lead over his former college roommate Gavin Green after the second round at the Saudi International in King Abdullah Economic City on Friday.
Perez has finished outside the top 20 just once since winning his maiden European Tour title at the Alfred Dunhill Links Championship in September, and he was impressive again as he claimed seven birdies to get to 10-under overall.
Malaysia's Green, who started the day with a share of the lead, birdied his opening hole before bogeying the 12th but picked up shots on the 15th, first and fourth to get within one.
A brilliant approach shot to the sixth hole helped him grab a share of the lead but he dropped a shot at the eighth to slip back to nine-under heading into the weekend.
Perez and Green share fond memories from their time as roommates at the University of New Mexico, and the pair will have plenty of time to catch up as they go head-to-head in the final group in Saturday's third round.
"We were roommates in college for four years and we are obviously very close. He played very well yesterday and I'm looking forward to playing together," Perez said of Green, who is chasing his maiden European Tour title.
"He's a great talent and he has been coming up and a long time, so it's only a matter of time before he breaks through."
Former U.S. Open champion Graeme McDowell stayed in contention for his first European Tour win since 2014 as he added a steady 68 to his opening round 64 to finish two shots off the lead.
Defending champion Dustin Johnson also recorded a 68 to stand in joint-eighth place on five-under, five off the pace.
(Reporting by Hardik Vyas in Bengaluru; Editing by Ian Chadband)
