Ireland’s Simon Thornton is one of seven players in a tie for the lead after the first round of the Portugal Masters as a total of 68 players broke par on the Oceanico Victoria Golf Course.

Seve Trophy team-mates Jamie Donaldson and David Lynn - who were on the losing Great Britain and Ireland side against Continental Europe last week - were among those to card six-under-par 65s, along with England's Graeme Storm, Spain's Alvaro Quiros, Chile's Felipe Aguilar, German Max Kieffer and the County Down-based player.

Defending champion Shane Lowry, third in the Alfred Dunhill Links Championship at the end of September, had to settle for a one-under-par 70.

Thornton carded two birdies and a bogey on the opening nine holes, but his round took off on the back nine, where he carded five birdies.

Donaldson had reached seven under before three-putting the eighth, his penultimate hole, for his only bogey of the day, while Lynn picked up three shots in his last five holes.

"The game has been feeling nice, the only thing that has not been great is that I have been feeling under the weather," said Lynn, who was taken ill during the Seve Trophy.

"I didn't feel too clever this morning but the sunshine should get rid of that soon and hopefully I am going to play myself into a few of these events coming up in Asia. I am 52nd in the world at the moment and I need to get back into the top 50, that's my agenda this week.

"It's essential I get back into the top 50 and to get well back into the top 50 would be nice, it would make things a lot easier for next year for doing the same sort of thing I have done this year (playing both the PGA and European Tour)."

Two more of Lynn's Seve Trophy team-mates, England's Chris Wood and Scotland's Scott Jamieson, were among a nine-strong group one off the lead, while a relaxed approach to the pressure of trying to keep his card paid off for Scotland's Chris Doak with an opening 67.

Doak is 112th on the Race to Dubai with only the top 110 after next week's Perth International keeping their full playing privileges for 2014.

"It's a great start," the 35-year-old from Glasgow told Sky Sports. "I said to myself three under each day you would be round about there so it's a good start.

"It's the total opposite this week to the rest of the season, just try to relax a bit more. I felt over the season I have been trying too hard when I have been up there. I came here on Sunday and had a few days to get used to the course and conditions.

"If anybody says they don't know what number they are (on the money list) they might be lying. You've got to know. For me I like to know what I have to do but it's just a different attitude this week which has been working so far."

Robert Coles is also struggling to keep his card and matched Doak's 67, but the Englishman will have had mixed emotions after leading by three shots when he played his first 12 holes in seven under par.

Coles, currently 164th on the Race to Dubai, then bogeyed the 13th and found water off the tee on the next to run up a double-bogey six before closing with four pars.

The 41-year-old has managed just one top-20 finish all season - in the very first event in South Africa which was reduced to 36 holes due to bad weather - and is still looking for his first European Tour victory in more than 360 events.