Story highlights

Mickelson leads by one at British Open

Stenson second after 65 to be nine under

McIlroy on -2 alongside Dustin Johnson

No. 1 Day and No. 3 Spieth scrape inside cut

Troon, Scotland CNN  — 

Water dripped from the peak of his cap, his rainsuit was sodden and he wore two gloves to better grip the club in the wet.

Miserable conditions for ducks, let alone golf.

But inside, Phil Mickelson was smiling. He knew he could hack it. He knew his near miss at a record-breaking 62 on day one wasn’t a fair-weather fluke. And he grafted through Friday’s mid-morning deluge for a two-under 69 to nudge his score to 10 under and remain in front at the halfway stage of the British Open at Royal Troon.

READ: The Open day two as it happened

“I really enjoy the challenge that this weather and these elements provide,” said the American, who needed a clip to keep his saturated hat on. “I thought it was a good round to back up the low round. I played kind of stress-free golf again.”

Mickelson caught the worst of the morning rain after a dry, still start.

He also knew it wasn’t going to be a procession, and emerging out of the in-out gloom came Sweden’s Henrik Stenson with a six-under 65 that was remarkable given the conditions, trimming Mickelson’s three-shot lead to one with two rounds left.

READ: Troon trumps Turnberry with American precedent

But it wasn’t just a duel in the deluge. While rain was the main theme, there was everything from dry and calm to wet and gusty,. The later starters copped the worst of it and the scores showed. Behind the leaders, Denmark’s Soren Kjeldsen and American Keegan Bradley climbed to a tie for third place on seven under, while defending champion Zach Johnson was fifth, two strokes back. In all, nine players were within six shots of the lead.

The 46-year-old Mickelson is bidding for his sixth major, perhaps tellingly on the course where compatriot Arnold Palmer won his sixth in 1962. Also in his favor is the fact that the last six winners of the Open at Troon have been American.

Mickelson, who hasn’t won a tournament since the 2013 Open at Muirfield, reckons the pressure is off him because he has already clinched the Claret Jug. “I would love to add to it, but having already done that was big,” he said, after pick-pocketing three front-nine birdies before the sky drained on Troon.

Sweden's Henrik Stenson ate into Mickelson's lead with an impressive 65.

Stenson, the world No. 6, is chasing his first major title at the age of 40 after finishing second behind Mickelson at Muirfield. He was also third in 2008 and 2010. In Stenson’s favor, the last three Open champions at Troon were also first-time winners.

“It’s always harder to push the first one over the line, I would imagine, than the sixth one,” he began in trademark deadpan fashion. “But at the same time he’s six years older than me, so I should be a little stronger, shouldn’t I?”

READ: Prestwick - birthplace of a legend

The pair will play together on Saturday, and Stenson added: “Phil’s not going to back down. He’s not going to take his foot off the pedal. I’m looking forward to the challenge.”

Mickelson would become the second oldest Open champion after Old Tom Morris, who was 46 years and 99 days when he won at Prestwick in 1867, but he is adamant age is irrelevant.

“From 10 years ago, when I was playing my best golf, I’m 25 pounds lighter, I’m in better shape, I’m physically stronger than I was,” he said.

“I feel better, and starting to play some of my best golf again. So I don’t see why there’s any reason why I can’t continue that not just this week but for years.”

Troon endured spells of heavy rain and gusty wind amid clearer patches on Friday.

The Californian, who just needs the U.S. Open to complete his career grand slam, says the 2004 Open at Troon – when he tied for third – was when the penny dropped how to play links golf. Work in the off-season of 2003 with short-game guru Dave Pelz helped him to hit lower shots with less spin to take advantage of the natural humps and hollows of a seaside course.

Rory McIlroy carded a level-par 71 on day two.

“This is where it really kind of turned for me,” he said. “This is where I stopped trying to overpower the golf course, where I accepted playing it as it’s designed, and not trying to find a new, better way to beat the course other than just straightforward golf. That’s probably why I love it so much.”

READ: McIlroy - I have not let golf down by missing Rio

Unable to make up much ground were the world No. 2 and U.S. Open champion Dustin Johnson and fourth-ranked Rory McIlroy, who shot 69 and 71 respectively to sit eight back, tied for 15th.

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However, world No. 1 Jason Day is a distant 11 shots adrift, while third-ranked Jordan Spieth and world No. 5 Bubba Watson only just scraped inside the cut on four over.

Veteran Ernie Els, the 2012 champion at Royal Lytham, missed out by one shot after a 76 marred by three double-bogeys.

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The 81 players who qualified for the weekend rounds will do well to remember that Scotland’s Paul Lawrie came from 10 shots back to win on the final day at Carnoustie in 1999.