Peter Lawrie and Ross Fisher were among the early front-runners as the Andalucia Valderrama Masters got underway in Sotogrande.
Lawrie, 36, birdied his opening three holes, while Fisher - currently 13th in the Race to Dubai standings - picked up shots at the first, third and fifth to join the Irishman on three under.
Both men then dropped shots to slip back to two under, but they remained in a tie for first place alongside Graeme McDowell, Francesco Molinari and Gareth Maybin.
US Open champion McDowell got his round off to a positive start with birdies at the first and fourth.
Molinari, meanwhile, birdied the second and fifth holes to ensure three members of Europe’s victorious Ryder Cup team were at the top of the leaderboard.
Northern Ireland’s Maybin was also at two under after birdies at the fourth and tenth holes, while Rafael Cabrera-Bello was a shot further back after three birdies and two bogeys on his front nine.
Race to Dubai leader Martin Kaymer, who can become the new world number one with a top-two finish this week, parred his first five holes to remain on level par, while Thomas Levet made a spectacular start to his round, following an opening double bogey six with an eagle two at the second.
Darren Clarke was another to enjoy an eventful morning, with three birdies and three bogeys in his opening eight holes.
