Shane Lowry shocked even himself as he was involved in a bizarre rules violation in the second round of the US Open.The Irishman absent-mindedly picked up his ball on the green without marking it on the 14th hole at Oakmont Country Club. GettyShane Lowry missed just his second cut in his past seven U.S. Open starts on Friday[/caption]Sitting nine-over-par after his first round, Lowry opened his second round with three bogeys and a double bogey in his first four holes.But things soon went from bad to worse for the 2019 Open champion, when he chipped his third shot well past the hole on the par-4 14th.He then strolled over collect his ball before putting, but crucially forgot to put down a coin and just picked it up.Television cameras captured the incident, and showed Lowry’s caddie Darren Reynolds looking on in disbelief as his player made the ultimate blunder.The world number 12 appeared to realise his mistake almost immediately, putting the ball down and calling a penalty on himself.But Lowry managed to see the funny side of things, as he was captured laughing it off with his playing partner Rory McIlroy.Golf rules state: “If the player lifts the ball without marking its spot, marks its spot in a wrong way or makes a stroke with a ball-marker left in place, the player gets one penalty stroke.”And after calling over a rules official and being issued his penalty, Lowry replayed his putt from the same spot, now putting for bogey rather than par. The 38-year-old then missed his putt by a foot, before tapping in for a double bogey.This had little impact on Lowry’s title hopes, as he was already well outside of the cut line at the time, and he later hinted the infamous Oakmont course and humid conditions had played a part in his mental lapse.Credit: X: @fried_egg_golfLowry’s caddie Darren Reynolds couldn’t hide his confusion as his player picked up the ball without marking it[/caption]Credit: X: @fried_egg_golfThe Irish golfer soon immediate realised his mistake and put his ball back down[/caption]Credit: X: @fried_egg_golfHe then laughed off the mistake[/caption]When asked about the incident afterwards, he laughed and said: “Probably one of the stupidest things I’ve ever done.“I just picked the ball up, had the ball in my hand, turned around to Darren and he basically said to me: ‘What are you doing?’ “Yeah, I put it back down and marked it and got on with it. I knew it would be a penalty, just wasn’t sure if it would be one or two (shots).“By then maybe my mind was somewhere else. But I still tried over ever shot, and that’s all you can do on a week like this.”And his marker blunder wasn’t Lowry’s only noteworthy moment on day two of the third major of the year, who made his frustrations known earlier in the day.After missing his par putt on the par-5 fourth hole, the golf star could be heard shouting: “F*** this place, f*** this place.”GettyLowry shared a joke with playing partner Rory McIlroy over his 14th hole gaffe[/caption]Despite making light of some of his antics, Lowry will have been hugely disappointed with his efforts, as he ultimately exited the tournament with a 17-over 157 total.This was a far cry from his last US Open outing at Oakmont, where he finished as joint runner-up to Dustin Johnson with a one-under-par score.Reflecting on what went wrong in this campaign, Lowry said: “I don’t know to be honest. I drove it in play a lot Thursday, did what I was supposed to do off the tee and then just didn’t have my game that I’ve had for the last while.“Then I really struggled on the greens and the round got away from me out here and that was it. They let it sort of do what they said it wouldn’t do, but that’s all fine, that’s the US Open.”“I just made obviously too many doubles, too many big mistakes and when I got a couple chances, I didn’t convert them.“I didn’t really do much right to be honest, other than I drove the ball as good as I’ve probably driven the ball in a long time. So, yeah, weird couple of days.”