Victor Perez continued his recent run of remarkable form to set the clubhouse target on day two of the 2020 Saudi International powered by SoftBank Investment Advisers.
Since claiming a maiden European Tour title at the Alfred Dunhill Links Championship in September, the Frenchman has finished outside of the top 20 just once, securing two runner up finishes in Rolex Series events and a top five at the World Golf Championships event in China.
That run has seen him rise to 41st on the Official World Golf Ranking and he continued to show his class in round two at Royal Greens Golf and Country Club, carding a 65 to move to ten under.
Major Champion Graeme McDowell was two shots behind after a 70, a shot clear of Italian Renato Paratore - who carded a 65 - Henrik Stenson and overnight co leader Gavin Green, both of whom were both in the early stages of their rounds.
Thai Jazz Janewattananond was at six under, a shot clear of Swede Marcus Kinhult and Italian Francesco Laporta.
McDowell three putted the 11th from 20 feet to leave Green in front on his own but both of them were soon passed by the surging Perez.
The 27-year-old turned in 31 with birdies on the 13th, 15th, 17th and 18th and, when he put an approach to three feet at the second, he was in double figures and led by four.
McDowell had birdied the 15th and he got up and down on the par five fourth to cut the lead to three before Perez could not do the same from the sand on the par three third.
The Northern Irishman used the contours of the green at the fifth to set up another gain from six feet but the lead was back to two as Perez played an excellent pitch into the fourth.
Perez then missed a six foot par putt on the sixth and McDowell was one back in the clubhouse as he parred his way home.
The leader was in trouble off the ninth tee but played an excellent second to ten feet and rolled home to lead by two once more.
Paratore birdied the fourth, seventh, tenth, 14th, 16th and 18th with a single dropped shot on the ninth.
Swede Stenson was two under through three holes, while Malaysia's Green had picked up a shot in his first eight.
Janewattananond birdied the 11th, 12th and 17th and, while he dropped a shot on the third, he made further gains on the fifth and seventh.
Laporta and Kinhult both recovered from bogeys with three birdies in rounds of 68.