Jon Rahm celebrated his competitive return to his homeland with an eight-under 63, but it was Ross McGowan who enjoyed the first-round lead at the Acciona Open de Espana.
Rahm thrilled the local fans with some high-quality golf befitting his status as world No 1, although he would have to settle for third place on the leaderboard as his score was bettered by McGowan and Sebastian Garcia Rodriguez.
McGowan has had just two top-10 finishes and has missed the cut 16 times since winning his second European Tour title in Italy almost a year ago, but he made the ideal start in pursuit of a third victory at the picturesque Club de Campo Villa de Madrid.
The 39-year-old carded eight birdies and an eagle at the 14th, getting round in 61 to post a new course record which will see him sleep on a one-shot lead ahead of Rodriguez.
"I think a few things have clicked," said McGowan, who began the event languishing at 167th on the Race to Dubai. "Some work I have done with the coach and some of the Covid restrictions somewhat easing off, I find mentally I am in a better place, so I think it is a combination of the two.
"I always seem to putt pretty well here and last time I played quite well here too, so looking forward to tomorrow."
Rodriguez has missed the cut in each of his last nine starts on Tour and is ranked 13 places below McGowan at 390th, but he also rediscovered some good form on home soil with a 62 blighted only by a bogey at the 11th.
"My start is fantastic, it's in my mind," he said. "I remember so many years ago playing the Open de Espana and it was a great moment, plus Jon Rahm is near the front and I am very good friends with him, we played a lot together and it is fantastic.
"So many fans, my friends and family are here. It's my dream. There were so many friends and family watching, this is my home, it is ten minutes from here, but it has been an incredible week so far."
Rodriguez's thoughts were echoed by defending champion Rahm, refreshed after some time off following the Ryder Cup in which he was the stand-out star for Europe, winning three-and-a-half points from his five matches.
"There are quite a few fans out here and they are rather enthusiastic, they have been cooped up for too long and they have the chance to come out and watch me play," Rahm said. "I haven't played on Spanish soil since this event two years ago, so they are golf hungry and they were great.
"From the beginning, every single shot and every single putt I made they were really supportive and every time I missed a shot they were extremely supportive as well, so that always helps."
Rahm fed off the enthusiasm from outside the ropes as he raced to six under after only eight holes before a bogey at 18 highlighted a "bit of a stumble" midway through his round, but he birdied the fourth, seventh and eighth to return a 63 and get within a couple of shots of the leader.
"It was a really good start," he said. "I played eight flawless holes and then a bit of a stumble from 18 through three, I didn't hit my best shots and was able to save a couple of pars to minimise the damage.
"After that I was able to play some good golf coming down the stretch, giving myself some chances, but obviously we saw what Ross McGowan shot this morning - 10 under is a heck of a round out here.
"I played good enough to maybe do it but you have to play flawless and make the putts, but overall, very happy with my round.
"Last time I played here was the first time on the golf course but it didn't take long to learn. You have to hit it really well off the tee, if I drive like I did early on and at the end when I was hitting it long and straight, wedges into every hole, then it is a doable score."
European Tour stalwarts Jamie Donaldson and David Drysdale both fired 64s to share fourth with Wil Besseling on a low-scoring first day, with 87 of the 132 starters breaking the par of 71.