Opening-round action was delayed for over three hours at the outset due to heavy rains. Players will return to the course this morning to complete the first round.
Robert-Jan Derksen is alone in second place at 5-under-par 67 with Andrew Sherborne, Julien Van Hauwe and Julien Clement tied for third one stroke back.
Arruti began his round in the second group off the front nine and birdied the second to get into red numbers. The Spaniard bogeyed the par-4 fifth to drop back to even-par but recovered that stroke with a birdie at the next.
The former Spanish Open Amateur champion caught fire on the back side and rolled in a birdie at the ninth to get to minus-2. Around the turn, Arruti birdied the 10th and 11th to continue his roll but found trouble again with a bogey at the par-4 12th.
Arruti spread three birdies over his final six holes to claim first place. He notched birdies at Nos. 14, 16 and 18.
'I played well from tee to green and was able to see the lines on the greens,' said Arruti. 'I holed some long putts and also had some short opportunities. I think I can still do good things and have confidence in my game so hopefully last year will be the last time I have to go to the (qualifying) school.'
Derksen, who knocked off Ernie Els to win the Dubai Desert Classic two weeks ago, continued his strong play this week. He got off to a hot start on the back side by sinking an eight-foot eagle putt at the par-5 11th. After a string of pars, Derksen rolled in a birdie at the par-3 17th to make the turn at minus-3.
On the front side Derksen faltered with a bogey at the par-3 fourth. He quickly recovered that stroke with a birdie at the next and later sank a birdie putt at the seventh before capping his round with a birdie on No. 9.
'I was eager to go out this week and play,' said Derksen. 'A lot of people asked why I didn't take another week off but I like the course and thought it was better to get playing again as soon as possible. I didn't have any expectations at all and it went my way today. It is nice to continue the form I had in Dubai.'
Clement, who won the last card at last year's Qualifying school, birdied the 11th and 12th holes, his second and third, to get off to a quick start. After three straight pars, Clement birdied the par-5 16th to make the turn at minus-3.
Clement rolled in his final birdie at the second to help complete a bogey-free round.
'I had a good start, three-under after seven, and after that I was just trying not to make any bogeys, hit the greens and make some putts,' said Clement. 'It is different playing on Tour compared to amateur game. Now it is my job. I still enjoy golf, love golf but now it is more difficult to play for winning. It is a different level.'
Van Hauwe had two birdies on the front nine, before mixing four birdies and two bogeys over his final nine holes.
Sherborne traded a birdie and a bogey on the third and fourth holes. On the back nine, he carded four birdies over a six-hole stretch, Nos. 11-16, to climb into a share of third place.
Carlos Rodiles is alone in sixth place at 3-under par through nine holes. A group of eight players is tied one stroke further back at minus-2.