Rory McIlroy veered from the sublime to the ridiculous to miss the halfway cut in the US Open as Lee Westwood and Shane Lowry remained firmly in contention at Oakmont.
Despite getting off to a brilliant start, McIlroy could only add a second round of 71 to his opening 77 to miss his first cut in a major championship since the 2013 Open at Muirfield and end a run of nine straight top-25 finishes in the game's biggest events.
In contrast, Lowry recovered from two early bogeys - the second caused when he called a penalty on himself - to shoot 70 and lie just two shots behind halfway leader Dustin Johnson, who had played 36 holes on Friday.
And Westwood birdied the 16th and 18th to repair some of the damage inflicted by a run of six bogeys in the space of nine holes to be just a shot further back after a roller-coaster 72.
At four under par, Johnson was a shot ahead of first-round leader Andrew Landry, with Lowry on two under alongside Spain's Sergio Garcia, France's Gregory Bourdy and American Scott Piercy.
Westwood was a shot further back alongside England's Andy Sullivan, former champion Jim Furyk and Daniel Summerhays, with Lee Slattery among the group on level par which included major champions Adam Scott and Louis Oosthuizen.
McIlroy had completed his weather-delayed first round on Friday with bogeys on his last three holes to finish seven over par, equalling his worst score in the event which provided his first major victory in 2011.
The only good news for the 27-year-old was that Thursday's early starters were then told they would not start their second rounds until Saturday morning, after initially being given a start time of 8:54pm on Friday evening - two minutes after sunset.
The combination of a session on the range with coach Michael Bannon and a more aggressive approach then paid off for McIlroy on day three as he birdied the 10th, 12th, 14th and 16th and then drove the green on the short par-four 17th, only to three-putt for par from 80 feet.
Further birdie chances went begging on the first and second before McIlroy's round imploded on the third, the world number three four-putting from around 10 feet to run up a double-bogey six.
Another bogey on the sixth left McIlroy on the cut line of six over par and his chances of making the weekend disappeared when he failed to get out of a fairway bunker on the ninth at the first attempt.
Lowry, who finished ninth at Chambers Bay last year, started his second round with a bogey on the 10th and also dropped a shot on the par-three 16th, but only after calling a penalty on himself.
"I hit a nice six iron into the right-hand side of the green and had a straightforward putt from 30 feet up the hill," the 29-year-old explained. "I addressed the ball and the ball moved back. I had to penalise myself. It's very frustrating in a tournament like that.
"I actually holed a great eight-footer for a bogey. I think if I would have missed that it would have been difficult to get back from there. That kind of kept me going, and from there on I just played good golf.
"To hole that second putt was massive for me and massive for my whole day. I miss that and all of a sudden I'm over par for the tournament. When you get over par you start to think 'Where can I pick up a birdie?' And you might start forcing it."
Lowry holed from 11 feet for birdie on the par-five fourth and picked up another shot on the sixth before saving par from 25 feet on the ninth after finding a fairway bunker off the tee.
Westwood had held the outright lead on five under after birdies on the first and fourth, but bogeyed five of the next six holes and dropped another shot on the 14th before rescuing his bid for a first major title at the 73rd attempt.
"I didn't hit the ball very well," admitted the 43-year-old, whose tie for second in the Masters extended his unwanted record of most top-three finishes in majors without a victory to nine.
"I struggled on the range this morning to find my swing and really couldn't find it all day today on the golf course until the last hole. I feel like I got a little feeling there. Maybe I'll find it for the third round.
"Just delighted the way I played. It was a professional round of 72. The mistakes I made weren't killers, weren't disastrous. They were only bogeys and then I finished strongly with two birdies on the last three holes.
"I didn't panic out there. Just kept trying to grind it out. The way I played today I could have blown myself out of the championship so it was good to grind it out, be under par and have a chance at the weekend."