(REUTERS) - Matt Kuchar battled dizziness and sought medical attention in the first round of the Canadian Open on Thursday, four days after his crushing runner-up finish at the British Open.

The seven-time PGA Tour winner shook off the dizzy spells, including one which came while he was marking a ball, to card a one-under par 71 that left him six shots back of the clubhouse leaders.

"I had a couple of spells where I got a little bit dizzy and I felt weak. I don't know where it came from," said Kuchar, who did not blame jet lag after flying to Canada from England.

"I've had plenty of time to get over the travel. Hopefully, it's just something that passes real quick."

Kuchar missed out on a maiden Major title on Sunday when fellow American Jordan Spieth produced a brilliant finish at Royal Birkdale.

Yet Kuchar, eager to move on from that stinging defeat, had four birdies over his first 11 holes at Oakville's Glenn Abbey Golf Club to move into contention, but was undone by a double-bogey and bogey over his final seven holes.

Kuchar is scheduled to tee off in the second round on Friday alongside compatriot Bubba Watson and Northern Ireland's Graeme McDowell.