That gave him a one shot lead over Australian Brett Rumford, Italy's Lorenzo Gagli and tournament host Gonzalo Fernandez-Castaño, who thrilled the home fans until a three-putt bogey at the final hole cost him a share of the overnight lead.
“I think I like Madrid,”said McGowan. “That was a much better round than I’ve been putting together recently.“I got off to a good start, birdied the first two, and just kept trying to hit good golf shots - that was the key. I kept finding the right spots on the greens and holing the putts.
The former Challenge Tour graduate failed to get up-and-down from the edge of the 15th green but responded to that bogey with a birdie at the next and finished with a pitch to two feet at the last for an amazing tenth birdie.Like McGowan, Rumford and Fernandez-Castaño are outside the all-important top 115 on The Race to Dubai, although the Spaniard has missed most of the season with a back problem.
Gagli finished his round with a hattrick of birdies to match their 65s to be one ahead of Italy’s Edoardo Molinari - the Ryder Cup star performing best of the morning starters in the Spanish capital.
Big-hitting home favourite Alvaro Quiros was amongst those on five under, with World Number One and defending champion Luke Donald a shot further back.
“I felt like I left a few out there,” said Donald. “A couple of careless mistakes but a lot of solid golf in there too.”