LA JOLLA: South Africa’s Louis Oosthuizen matched US clubhouse pace-setter Russell Henley for the overall lead when darkness halted Thursday’s first round of the US Open, where Phil Mickelson struggled in his bid to complete a career Grand Slam. Oosthuizen, the 2010 British Open champion, made three consecutive birdies to close his first nine after a 10th-tee start, then added an 11-foot birdie putt at the fifth to reach 4-under. That’s where he stood when he stopped on the 17th green, level with Henley’s four-under par 67, when sunset fell with 36 players from the field of 156 needing to finish the opening round Friday after a 90-minute morning fog delay. World number 18 Oosthuizen, whose five major runner-up finishes since his win 11 years ago include last month’s PGA Championship, sank birdie putts from just inside 20 feet at 12, another from 19 feet at the par-3 16th, a 25-footer at 17 and a tap-in at 18. World number 63 Henley, an American who hasn’t won a PGA title since the 2017 Houston Open and lacks a top-10 major finish, made three birdies and a bogey on both the front and back nines to set the early pace at Torrey Pines. Italy’s Francesco Molinari, the 2018 British Open champion, and Spain’s Rafa Cabrera Bello, who holed out from just inside 60 feet to eagle the par-5 18th, shared second on 68. Among those who finished in gathering gloom was Spain’s third-ranked Jon Rahm, who shot 69 after spending much of last week in Covid-19 quarantine. Four-time major winner Brooks Koepka, coming off right knee surgery in March, and US compatriots Hayden Buckley and Xander Schauffele were also in the clubhouse on 69. A day after his 51st birthday, hometown hero Mickelson stumbled to a 75 with three bogeys in his first six holes. He recovered with a 10-foot birdie putt at the 17th but bogeys at six and seven saw him into the clubhouse eight off the pace. Mickelson became golf’s oldest major winner last month by taking the PGA Championship at Kiawah Island to capture his sixth career major title. But the US Open has eluded the 30th-ranked left-hander, who has settled for a record six runner-up showings. Mickelson hopes to join career Grand Slam winners Tiger Woods, Jack Nicklaus, Ben Hogan, Gary Player and Gene Sarazen. Several top stars raced sunset to finish the round in twilight gloom. Four-time major winner Rory McIlroy closed with an eight-foot birdie putt to open on 70, bouncing back after bogeys at the 12th and par-5 13th holes. World number one Dustin Johnson opened on 71 while defending champion Bryson DeChambeau shot 73, undone by three consecutive bogeys starting at the par-3 11th.