Alejandro Cañizares took the early lead on a morning of expected low scoring at the Portugal Masters at Victoria Clube de Golfe.
The tournament is celebrating its tenth anniversary this season and has always been known as a low-scorer, with Andy Sullivan claiming the title last year at 23 under par.
With very little rough, some players in the field had suggested a 59 was a distinct possibility this week but Cañizares would have his work cut out to achieve that, having reached six under after 11 holes.
Padraig Harrington was a shot behind having reached the turn in 31, with six players at four under and just seven of the 66 morning starters over par.
Cañizares started on the tenth and birdied the 11th before an eagle on the par five 12th. Further birdies then followed on the 14th, 16th and 18th as he turned in 30.
Harrington also began his campaign on the back nine and he flew out of the blocks with birdies on the tenth, 11th and 12th. He then chipped in from the side of the green for an eagle on the short par four 15th and hit the summit with a gain on the 17th before bogeying the next.
South Africans Thomas Aiken and Trevor Fisher Jnr were then four under after 12 holes with countrymen George Coetzee and Justin Walters at the same mark having played a hole less.
Cañizares' fellow Spaniard Nacho Elvira was also four under after 11 holes, alongside Swede Kristoffer Broberg who turned in 32.
A group of 17 players were then at three under, with defending champion Sullivan a shot further back after ten holes. Playing partner Alex Noren was also at that mark with remaining member of the trio Thomas Pieters at one under.
