Erik van Rooyen carded five birdies on the back nine to move into a one-shot lead at the Trophee Hassan II.
The South African was two shots back heading into the third round, but a five-under 68 saw him move clear of Jorge Campillo, another big mover on Saturday.
“I struggled with my rhythm, my tempo in the beginning and I think I just kind of found my flow on the back nine,” Van Rooyen told the European Tour’s website.
“What we’ve been doing up until now has been great, so we’ll just keep doing that.”
Campillo had just one blemish – a bogey at the 11th – during his 69, putting the Spaniard firmly in contention.
Sean Crocker and David Lipsky had shared top spot at the halfway stage, yet the former hit a costly double bogey at the 16th while the latter was one over for the day, his eventful round including five bogeys.
Still, Crocker sits alone on six under, just ahead of a four-man group of Julian Suri, Wade Ormsby, Lee Slattery and Grant Forrest.
Jordan Smith, who has been in the mix all week, signed for an even-par round of 73 to join Lipsky and Masahiro Kawamura on four under.
— The European Tour (@EuropeanTour) April 27, 2019