Dan Walker has given the European Championship football a break briefly:

Speaking of something big, Sergio Garcia screams one out of the fairway bunkers on 15 and it skips to the fringe of the green. If ever a shot summed up someone 'going for it' on a major Sunday, that was it.

Another something big is the putt Dustin Johnson has for birdie on 14. it's got three putt written all over it.

Here's the first, decent weight, five feet left.

Shane Lowry could be given an opportunity courtesy of this controversy. He's just missed the sand next to the green on 13 but has a tricky chip. He whisks it out of the long grass and leaves himself around eight feet for par. In shes goes and up goes the Lowry fist with a clench. He's sensing something big.

Steve DiMeglio, USA Today sports reporter, talking on BBC Radio 5 live: "The rules of golf are so long and so complicated. It looks like we are talking about the ball moving and not addressing the ball. Dustin's practice swings by the ball may have caused it to move. 

"All I know is that Dustin hasn't played as well since he got told on the twelfth."

Randall Mell of the golf channel sums up the frustration of many within the sport.

We could be about to see one of the most controversial moments in the sport for some time indeed.

BBC Radio 5 Live

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Iain Carter
BBC golf correspondent at Oakmont Country Club

"What is being investigated is Dustin's putt on the fifth hole.

"The rule official asked did he ground the club and he said no, so he played the ball from where it rested.  

"It looks like it could be a two stroke penalty. Two penalties, each one stroke.

"It's very contentious."

So if you've just flicked this live text on, Dustin Johnson leads by one as things stand... BUT... he is under scrutiny for an incident on the fifth green where his ball moved before he struck it. 

Officials have told DJ they want to chat to him about it after the round so we are waiting on whether he faces a penalty.

As we speak, Shane Lowry - second on four under - finds the sand on 13 and has the same up and down Johnson faced a moment ago.

Then come Scott Piercy on three under, with Sergio Garcia and Branden Grace on two under.

Don't go anywhere.

Sergio Garcia's run of miraculous hole outs and putts ends as he leaves one short on 14. You've got to hit them Sergio. 

Scott Piercy is the silent assassin here for me. All day he's just sneaked around dressed in black like the Milk Tray man. He makes par on 14 and is three under.

Piercy, 32, has won on the PGA Tour three times and has one top-10 finish in a major.

It's safe to say there is sympathy for Dustin Johnson from fellow pros on social media.

He stands in the sand on 13 and plays a brilliant escape to leave six feet. That was a brave effort.

Over on 12 Shane Lowry is looking to swing the momentum back his way once more. This pitch could set up birdie... or will it be eagle... the ball rests just shy of the cup for tap-in birdie.

Back to Johnson... good hold. Good, confident putt and from the bunker that is a superb result for the man of the moment.

Image source, Getty Images

Jay Townsend
Former American professional golfer on BBC Radio 5 live sports extra

"I have never know anything like this. 

"They might as well just tear down the scorecards.

"Either he grounded the club or he didn't. They can decide themselves they don't need to speak to him."

Iain Carter
BBC golf correspondent at Oakmont Country Club

"The other players have been told that Dustin's score is being looked into.

"Nobody knows what's going on and neither do we.

"We think they are going to speak to Dustin after the round, which means someone could make the winning putt on the 18th and not realise it."

Popular golf journalist Brian Wacker is confident Dustin Johnson will be docked a stroke.

We do not yet have confirmation. The easiest thing for DJ to do now would be to hole his bunker shot here and go on to win by two.

My oh my, what are we saying.

Bogey-free Johnson is on the par-three 13th and his lazy swing lofts the ball left of the green into sand. What's more is he has little green to work with from there. The best he's going to get you'd think is 12-15ft for par.

Has the discussion he had with a rules official scrambled the most important part of Oakmont right now - the six inches between his ears.

Dustin Johnson can widen the gap with this birdie putt on 12, not enough legs on it though and it's par.

Image source, Getty Images

Rules officials want to review the footage of the fifth green with Dustin Johnson after he finishes his round. He has been told it could lead to a penalty - there is still confusion as to whether it will be one or two shots if upheld - and the other players have been informed. 

Johnson fell foul of a rule about grounding a club in a bunker when he was poised to win the PGA Championship in 2010.

Could lightning strike twice. Nobody wants the winner decided in the scorer's hut. Quite how Dustin Johnson is continuing to play is beyond me. Surely a decision needs to be taken out on the course.