Scottish golfer Marc Warren birdied the first six holes in shooting an 8-under 63 and taking the Portugal Masters lead on Thursday.
Warren bogeyed the seventh hole but followed with a par and yet another birdie to make the turn in 29. He added two more birdies on the back nine to finish the first round one shot ahead of American David Lipsky, who also birdied six holes on the front nine in a 64, tied with four other players.
"It's an absolutely perfect start," Warren said. "Everything was going right for me, just the right numbers and landing it close and a couple of tap-ins."
Padraig Harrington was tied for 12th after carding a 5-under 66, the same score as Paul Lawrie.
Defending champion Andy Sullivan was at 4 under, along with Sweden's Alex Noren, who is trying to win for the fourth time in nine European Tour events.