But his form trailed off slightly in the gathering gloom as he bogeyed the ninth and 10th holes of his second round before play was finally called off for the day.

"I'm very comfortable where I am at the moment," said Clarke who ended the day at four under par - two shots behind the leader.

"Hopefully I'll go back out on Saturday morning and recapture some of that form.

"I played really well all day, and made very few mistakes. A first round of 66 was a pretty fair score."

Clarke admitted he found the second round of the day - after heavy rain washed out the opening day's play - much tougher going.

"I didn't play quite so well and was grinding it out a little bit," he said.

"Unfortunately I finished with two bogeys on the last two holes."

I really enjoyed the atmosphere

Scotland's Paul Lawrie finished at level par for a share of fifth place but was not entirely happy with his game.

"I didn't play very well," he said.

"I hit only six or seven greens but I chipped and putted well. To shoot level par like that means, hopefully, there are better things to come.

"The pins are all in high positions but the greens are perfect. But if you're playing safe you have long and difficult putts."

No excuses

Debutant Justin Rose, who finished at one over in an encouraging performance, was also happy with his first experience of Augusta.

"It's a pretty decent round here for the first time," he said.

"We were working hard out there but I really enjoyed the atmosphere."

Ireland's Padraig Harrington, who ended the day at six-over with six to play, made no excuses for his disappointing display.

"I got off to a bad start," he admitted.

"I made a couple of poor drives and that killed me all day.

"I didn't charge but I made a few club selection mistakes which compounded a few errors. It wasn't that tough a day."