He finished the first round just two off the lead set by compatriot Dustin Johnson, who carded a seven-under 65 in what were likely to be the best conditions of the week.

“You need to put yourself in good position to have some shots to spare and not worry about a cut line or anything [because] we never know with the forecast,” said Spieth, who tees off at 2.34pm.

“It’s definitely going to be a brutal day. We just don’t know when the rain is going to start, when it’s going to stop, if it’s going to come back.

“I think it will be a true Scottish day that we all should enjoy the challenge ahead.”

Johnson was one of only five players to be bogey-free all day as he took advantage of the favourable morning conditions alongside Spieth.

He was conscious of the need to make hay while the going was good and believes his round proved – not that he thinks he needed to – he was over his US Open heartbreak after three-putting the final green at Chambers Bay to hand the title to Spieth.

“Everybody knows the weather Friday and Saturday is going to be very difficult so I thought it was very important to get off to a good start and try to make as many birdies as I could because the next couple days it’s going to be very difficult,” Johnson said.

“I played really well at Chambers Bay and then it carried over.

“There’s really no bad feelings from that, only good. There’s really nothing to be upset about.

“It was a little disappointing not to get in the play-off at least but I don’t really dwell in the past too much.

“You can’t really change it, so there’s no reason to worry about it.”

Despite his impressive form, Johnson’s lead was just one shot as compatriots Robert Streb and Zach Johnson, 1999 Open champion Paul Lawrie, Australian Jason Day, Sheffield’s Danny Willett and a resurgent two-time major winner Retief Goosen all carded 66s.