Brookline — South Africa's M.J. Daffue, making his major debut, birdied four of the first seven holes to grab a three-stroke lead early in Friday's second round of the US Open while overnight leader Adam Hadwin stumbled early.
Daffue, a 33-year-old from Pretoria, stood on 6-under par through seven holes Friday at The Country Club, three strokes ahead of Canada's Hadwin and four others, including four-time major winner Rory McIlroy.
A journeyman on developmental tours, Daffue said he didn't plan to try and qualify for the US Open but locked up a US PGA Tour spot for next season and changed his mind at the last minute.
Daffue, out in the second group off the first tee, sank a 12-foot birdie putt on the first hole to match Hadwin, took a three-putt bogey at the par-3 second to fall back, then made a birdie putt from just outside nine feet at the fourth.
At the par-four fifth, Daffue found a greenside bunker off the tee, blasted to just inside seven feet of the cup and sank the putt to seize the lead alone. He followed with a birdie at the seventh to stretch his advantage.
Hadwin, who fired his lowest career major round, a four-under 66, to seize the lead on Thursday, began Friday with a 10-foot par save at the 10th hole and a bogey at 11 to fall back to 3-under.
Hadwin, the first Canadian to lead a US Open since Mike Weir in 2009, has never been better than 24th in 19 prior major starts.
Alternate Hadwin made it into the field when England's Paul Casey withdrew last week due to a back injury.
Sharing third with Hadwin after shooting 67 on Thursday were third-ranked McIlroy, England's Callum Tarren, Sweden's David Lingmerth and American Joel Dahmen.
Afternoon storms were forecast for about the time defending champion Jon Rahm and McIlroy were set to tee off at the 7,254-yard layout.
Gusting winds were expected but a softened course could benefit the contenders once the lightning danger passes.
Any delay likely means the cut won't be made until Saturday and would set up a hectic charge for the field to try and finish 72 holes by sunset Sunday.
McIlroy, chasing his first major title since 2014, comes off a victory in last week's PGA Canadian Open. Not since 1934 has a player won the week before and then captured the US Open.
The 33-year-old from Northern Ireland produced his 29th major round in the 60s on Thursday. When he has opened majors with back-to-back rounds in the 60s, McIlroy has won three times.
DJ's 68 is LIV's best
American Dustin Johnson, the 2016 US Open and 2020 Masters champion, had the lowest score Thursday with a 68 among the 15 LIV Golf players in the field of 156, a group that went a combined 53-over par in the opening round of its first event against US PGA Tour talent.
With the richest purses in golf history, Saudi-backed LIV Golf has lured players from the PGA Tour, which banned 17 current and former members from its events last week after they played LIV's debut event in England.
A regular-season LIV event offers $25 million in prize money, $7.5 million more than the US Open pays.
The US Golf Association decided to stay with its qualifying criteria and didn't ban LIV Golf players for this week, but USGA chief executive Mike Whan warned such a move was possible in the future.