Story highlights

Spieth, Koepka, Kuchar lead the Open at -5

Casey, Schwartzel at -4

Played at Royal Birkdale in northwest England

Royal Birkdale CNN  — 

He’s been sharing tips on high-performance sport with Olympic swimming legend Michael Phelps and it showed in a golden opening round from Jordan Spieth at Royal Birkdale.

Ice-cool in ice-white pants, the world No. 3 charged to a share of the lead after day one of the 146th British Open.

The Texan, with the bow-legged gait of a cowboy, threaded his way through the breeze and bunkers on England’s northwest coast in 65 shots for five under par.

He ended the day tied with last month’s US Open champion Brooks Koepka and fellow American Matt Kuchar. Former Masters champion Charl Schwartzel and England’s Paul Casey ended four under.

Spieth’s round wasn’t perfect – or at least, he rated it a nine out of 10 – but the 23-year-old found a way to make it effective.

A “top-five, probably” round in majors, he called it, and “extremely important” given Friday’s forecast for spells of heavy rain and strong, gusty wind.

It was also significant given the efforts of top-ranked Dustin Johnson, who strode with the loose-limbed prowl of a panther, but could do no better than one-over 71 in balmy afternoon conditions.

READ: Tips from Federer, skydiving, mind games – pros prepare for the Open

READ: Links, lies and ladybirds – 7 things to know about the Open

READ: Beacons of beauty – the world’s best golf links

Sticky spot

Spieth’s perpetual gum chewing told the story: with a flourish, and he liked the shot; with disdain, and he’d hit a bad one.

His putting wasn’t always a match for the dead-eye shooting of his double major season in 2015. Often his palm-down hand gesture would will the ball to slow as it charged holewards.

The longer game, too, was occasionally off kilter, mainly blown about by an early Irish Sea wind, which has permanently bent the Birkdale trees to its ferocious will over the years.

On the 10th, Spieth – black puffy vest over grey, longsleeve shirt – pulled his second shot onto a grassy bank left of the green.

A little girl spotted it and handed it to her dad. The father was mortified and ordered her to drop it.

The ball was replaced before Spieth arrived, but recognising a sticky spot he told caddie Michael Greller, “Let’s just get out of here with a five.”

But he pulled off a miraculous recovery for a tap-in to save his par four and remain three under.

‘Red-faced’

From the lofty tee looking down over the 13th, Spieth carved his drive right. “Fore,” he bellowed, shocking oblivious passers-by.

The ball found the right rough, and while Spieth was assessing his options at its side, an orange-jacketed marshal, trying to stop the gallery using camera phones, trod on it.

Spieth threw his hands in the air, shook his head and called over the match referee. He was awarded a free drop.

Preparing for his shot, he kept up the perpetual conversation with Greller, a former maths teacher. “Wind 45 degrees off the right? No need to be aggressive here. I like this club, huh?”

He fired the ball forward with a nine-iron, a beauty onto the green, to gasps and cheers from the crowd. They’ve taken to the young master over here.

The offending marshal’s red face clashed with his jacket, but he told CNN he hadn’t seen the ball.

Did Spieth say anything to him? “He heffed and jeffed, as they do. Never mind, he’ll get over it. He’s on the green now.”

He more than got over it, and added further birdies at 14 and 17 either side of a stunning par save from the bunker on 16 – his “shot of the day” – for a two-stroke lead over the then clubhouse leader Ian Poulter of England.

“Things are in check. It’s just about keeping it consistent,” said Spieth, who fueled himself up on a breakfast of eggs, bacon, avocado on toast and orange juice.

His meeting with Phelps, the most decorated Olympian of all time, occurred on a recent vacation to Cabo San Lucas with a crew that also included NBA legend Michael Jordan, former Masters champion Fred Couples and NFL star Dwight Freeney.

READ: Spieth renews Tiger Woods comparisons with 10th title before 24

Vegas, baby

The powerful Koepka took four weeks off after his breakthrough major win at Erin Hills, hitting Las Vegas. Hard, by all accounts.

But back in the gym and relishing another round of links golf after missing the Open last year, the 27-year-old Floridian eased alongside Spieth at five under courtesy of a holed bunker shot for eagle on the 17th.

READ: How a car crash shaped Koepka’s US Open destiny

“I love links golf,” said Koepka, who cut his pro teeth on the European circuit.

“I just wanted to get back inside the ropes. I wanted to have those juices flowing. It’s a major championship, and if you can’t get up for that, you might as well go home.”

The pair were later joined by Kuchar, who is one of the best current players without a major, and well placed after one round to continue the trend of seven first-time major winners.

He was reminded in his news conference that five of the last six Open champions have been 39 or older.

“Regardless of your age, if you’re in this field you have a dream to win the title,” said the 39-year-old.

Do you know who you are?

The gentle post-lunch zephyrs couldn’t blow away Rory McIlroy’s recent malaise.

The Northern Irishman, who won the last of his four majors in 2014, cut a dejected figure early on and was five over through nine, and playing third fiddle to partners Johnson and Schwartzel.

“I was thinking, geez, here we go again,” McIlroy told reporters. “But JP [his caddie, JP Fitzgerald) he reminded me who I was, basically. He said, ‘You’re Rory McIlroy, what are you doing?’”

McIlroy rallied after turning for home, with three birdies in his last four holes to end alongside Johnson.

READ: Rory McIlroy to avoid social media after spat

Poulter, who was second to Padraig Harrington the last time the Open was at Royal Birkdale in 2008, has missed the last five majors with a foot injury and had to come through qualifying to gain his spot.

But it paid off as he shared fifth with the tie-wearing Justin Thomas, green-glove wearing Charley Hoffman, Spanish Ryder Cup star Rafa Cabrera-Bello, England’s Richard Bland and another qualifier Austin Connelly, 20, a Canadian who grew up in Texas and is friends with Spieth.

Visit CNN.com/golf for more news and videos

Defending champion Henrik Stenson ended one under, while Phil Mickelson, whom the Swede beat in that epic duel 12 months ago, finished three over.

Thursday is done. Friday could be brutal at Birkdale.