But Dustin Johnson is still hitting shots. He's through the green on 16 and will have to get up and down for par.

is Scott Piercy going to be that unthinkable major winner. The one no one saw coming like Mike Weir, Charl Schwartzel, etc.

He will have a birdie putt on 17 to move to three under. 

Branden Grace makes bogey on the same hole and moves back to level par.

And we have drama on 15... Shane Lowry three puts and makes bogey, back to two under. He was up and walking as soon as he hit the ball, he knew it was wide.

These crowds in Pennsylvania are seeing drama superior to any US TV box set I think you'll agree.

It's got a bad guy in the shape of the USGA, an innocent victim in Dustin Johnson, an opportunist in Shane Lowry.

Eat your heart of Dallas, eat your heart out Breaking Bad...

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

"You can see from the logo on the ball that the ball moves. I don't think he is going to get a penalty though. 

"But by the USGA making these players aware, they have completely changed the psychology of all the players.

"It's crazy, nuts.

"Irresponsible and farcical are the two words that come to mind."

I've played games of crazy golf with less controversy than this.

As Dustin Johnson converts his tap-in on 15 for par we still don't know if he will be docked one shot, two shots, or no shots at all.

-4 Dustin Johnson (US) (15) 

-3 Shane Lowry (Ire) (14)

-2 Scott Piercy (US) (16)

-1 Jim Furyk (US) (18), Branden Grace (SA) (15)

E Sergio Garcia (Spa) (16) 

Dustin Johnson has a tough read here on 15 from range. There's an upslope to deal with... he does that nicely and as the ball breaks left of the slope it will leave him three feet for par.

On 16 Sergio Garcia is close for par but close is no good at this stage back to level par. His playing partner Scott Piercy makes it two bogeys on that hole by leaking a putt left.

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

"I can't explain what's going on. It's beyond comprehension. This is America's national Championship and no one knows whats going on."

Sergio Garcia is out of the bunker on 16 and has a lengthy putt left for par. His tournament may be up here.

We have the first birdie of the day on 18 - yes, that's right a birdie at the last to win it is a tough ask.

This time it's Zach Johnson as he gets into the clubhouse at two over. He just couldn't find that extra gear this week to threaten but as is typical of the two-time major winner, he dug in.

And all the while Scott Piercy is just ticking along nicely on three under. He has a putt so long he's stood in Alaska. The 16th green is a big one and the ball almost crosses all of the real estate. It won't make the hole and will in fact leave a testing distance for par.

Jason Day from the sand take two... the ball doesn't escape. He's going to post a big number here and his US Open is over on 17.

Back to Shane Lowry on 14... "worst putt I've hit all week", he says as the ball curls wide.

Are you gripped by this? It's confusing the heck out of me but I like it.

Image source, Getty Images

Shane Lowry has a birdie putt - an outside chance on 14. 

The Irishman is fully aware of Dustin Johnson's dance with the rulebook so even he is left wondering if he leads the US Open right now or not.

This is like a football team being 1-0 up but being told they are perhaps actually drawing 0-0. 

Jason Day's day is over. He chips from one bunker to another as he's seeking a hole out but greed is not good in this instance.

To Lowry, like a Meatloaf song this putt is long and never-ending. His ball comes to a halt three feet from the hole.

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

"This is unfortunate as up until that point it had been a great championship. There will always be a cloud over this major now. I am actually embarrassed for the USGA."

According to the rules, Dustin Johnson did not address the ball.

But what do the USGA think.

DJ is teeing it up on 15. A 479-yard par four, just what you want to be faced with eh. He's in the rough but not sitting too badly.

And with the look of a man who is battling demons, Dustin Johnson misses his par save on 14. The break on a short putt did for him. I did say it had three-putt written all over it.

How do these major Sundays always throw up such drama?

The lead is tied, for now. Shane Lowry, over to you...

Ron Kaspriske is senior editor at Golf Digest:

Image source, .

Dustin Johnson finished sixth at the Masters last year. He's been top-10 in ever major since bar the Open when he was brilliantly placed but struggled on the final day.

So have we been foolish? Is he a star who has not got their deserved media love simply because he's not lifted a major title?

Now is his time surely? Or are the golfing Gods going to rob him (again)?