Spanish duo Pablo Larrazabal and Pablo Martin were among the early leaders as the Portugal Masters began at Oceanico Victoria Golf Course.
Alfred Dunhill Championship winner Martin reeled off a hattrick of birdies from the sixth to move to four under par through 11 holes, and take a share of an early five-way tie for the lead.
He was joined by compatriot Larrazabal, as the former Sir Henry Cotton Rookie of the Year mixed five birdies with a single dropped shot at the 13th.
Also going well was David Howell as the Englishman looked to return to form. The four-time European Tour winner has been plagued by injuries in recent years but finished eighth at last week's Alfred Dunhill Links Championship and started with four consecutive birdies in the Algarve.
His compatriot Anthony Wall and Scot Steven O'Hara were also four under after ten and eight holes respectively.
