Matthieu Pavon opened with an 8-under 63 featuring and eagle at the par-514th and a bogey at the par-4 10th to take the lead at the acciona Open de España presented by Madrid.
The Frenchman has recorded five top-10s this season on the DP World Tour, including at last week's Alfred Dunhill Links Championship.
"The confidence is back from a small tournament I played in France," he said speaking of the Open d'Arcachon two weeks ago. "That was a local tournament and I changed my driver, changed my putter, kind of freshened everything a little bit and I finished second over there.
"I brought that to the Dunhill and finished sixth so lots of positives from the last three weeks and I'm trying to just build on it.
"Last year I had a great finish here so I just kept trying to bring back all the souvenirs from that a little bit and it really helped me today.
"I feel pretty good. I hit a lot of great shots and from tee to green I was really solid. The putter was also great and overall I was amazed by the play I had today."
The Netherlands' Wil Besseling carded a 64 to take solo second place at 7-under.
"I have to say from last week to this week it has been a massive improvement and we always try to make small steps but I guess this was kind of a bigger one," said Besseling.
"I have had this before in previous years coming from Dunhill and struggling in the wind and the rain and the cold, and then coming here I see the lines. I mean visually it is so different, obviously the weather as well, so I feel right at home here and it has showed in the past and again today.
France's Mike Lorenzo-Vera, England's Eddie Pepperell and Portugal's Pedro Figueiredo are tied in third place at 6-under.
Defending champion Jon Rahm who has won four of the past Spanish Opens, is four shots back at 4-under.