Darren Clarke and Graeme McDowell are four off the pace after firing opening three-under 69s at the Scottish Open at Castle Stuart.
Clarke started with three birdies but despite also managing an eagle, his round included three bogeys.
McDowell moved to four under after 17 but finished with a frustrating bogey six at the last after finding trouble.
Michael Hoey start with two birdies and an eagle but fell away to a 72 while Gareth Maybin shot a 73.
Peter Lawrie is the leading Irishman after a 68 with Padraig Harrington, Paul McGinley and Shane Lowry joinint Clarke on 69 and Damien McGrane finishing on 73.
After starting at the 10th, Clarke picked up three immediate birdies but his momentum was then halted by successive dropped shots on 15 and 16.
A birdie at the 18th and eagle three at six left him on four under but he dropped a shot at his closing hole after finding a bush with a greenside chip.
McDowell went out in one-under 35 but after picking up three birdies he finished on a disappointing note with a bogey at the par-five 18th.
Hoey started at the 10th and quickly moved to four under as he followed opening birdies with an eagle on 12.
But Hoey lost his way at the turn as he dropped shots on 18 and the 1st and further bogeys followed at the fifth and seventh.
Maybin also started at the 10th but after moving to the turn in one under, three bogeys saw him dropping down the leaderboard.
With Lee Westwood sharing the lead on seven under with little-known Chilean Tullo, Colin Montgomerie, Luke Donald and defending champion Edoardo Molinari all finished on five under.
The trio are in a group that are one behind Sweden's Peter Hanson, in-form Dane Thorbjorn Olesen and George Coetzee from South Africa.
Montgomerie, who skippered Europe to Ryder Cup victory last year, started strongly as he attempts to secure the top-five finish he needs for a chance of securing a place in the Open for the 22nd consecutive year.