(Photo credit: Mike Cardew / USA TODAY NETWORK via Imagn Images)

Padraig Harrington shot a 5-under-par 65 to take a one-stroke lead over a hard-charging Thomas Bjorn halfway through the ISPS Handa Senior Open on Friday at Sunningdale in Berkshire, England.

Harrington climbed the leaderboard to 8-under 132, one over Denmark's Bjorn and defending champion K.J. Choi of South Korea. Bjorn shot a sterling 7-under 63 to catapult into contention, and Choi posted a 67.

Harrington had five birdies, including at Sunningdale's first and last holes, while keeping his scorecard clean of bogeys. The Irishman has already collected two senior major titles -- the 2022 and 2025 U.S. Senior Opens -- and now he's starting to close in on his third.

'I rode my luck a lot today. Got my head in the game,' Harrington said. 'Did a lot of good stuff mentally. Short game was sharp.'

To Harrington's point, he said he had 'three crazy things' distract him during his round -- a falling acorn while he was playing a shot beneath a tree, a bug landing on him during a backstroke and a leaf falling in front of his ball.

'I wouldn't want to play like that -- well, I would like to score like that the next two days, but I wouldn't think I'm going to get away with it,' Harrington said.

Bjorn only shot an even-par 70 in the first round but shot out of the gates Friday with four birdies in his first five holes. After another birdie at No. 9, he holed an eagle at the short par-4 11th.

'Hit a great drive and just clipped the overhanging tree and fell down,' Bjorn said of No. 11. 'It was one of those where you just kind of go, well, thank you very much.'

Bjorn admitted he was 'very angry' with himself over a ho-hum first round, which ended with a double bogey.

'Just got out here in that mode of I know I played well yesterday and I was hitting the ball well,' Bjorn said. '... Wanted to get off to a start and hit a great shot on 2 which it's not like a given birdie, and then I hit some good shots from there.'

Choi could have been higher up the leaderboard if not for consecutive bogeys at Nos. 16-17 taking him down a few pegs.

'I'm still very nervous and very exciting,' Choi said. 'Very good player stronger, more stronger every year. So my game is every day new game, new start, patience, pray a lot. So my heart is a little stable, right? Not up and down.'

Australian Cameron Percy (65), Justin Leonard (65), Ernie Els of South Africa (67) and Ricardo Gonzalez of Argentina (67) are tied for fourth at 6 under par.

First-round leader Steven Alker of New Zealand followed an opening 63 with a second-round 73 to drop back to 4 under.

--Field Level Media