Up ahead, Rory McIlroy has laid up with his second shot and then fired his third straight over the flag, spinning the ball back down towards the hole.

A birdie to finish? No. Sums up his round a little bit. Close but not quite. A two-over 73 rarely gets the job done on a Sunday.

And Russell Henley finishes up too. The long-time leader closes with a three-putt bogey and a five-over 76 to end the tournament where he started it, at level par.

Jon Rahm, meanwhile, is on the practice greens. Just in case. But surely he won't need that putter again tonight?

He's being held up by the penultimate group of Rory McIlroy and Russell Henley finishing their rounds on the 18th green.

They're nearly done.

Here we go then, the all-important second shot.

Can Louis Oosthuizen get out of this heavy rough on the left of the 18th fairway and give himself a shot?

Jon Rahm has walked a mile, pacing up and down over this past half hour. He'll be worn out if Oosthuizen does miraculously take this to a play-off...

Louis will just want to give himself a chance. To get on or close to the green in two.

Not a great tee shot again - it's in the rough and the lie doesn't seem brilliant at first glance.

So the equation is simple, Louis Oosthuizen needs an eagle on the par five 18th to force a play-off.

If you don't remember, he got an eagle on the par-five 18th on Saturday...

Thumbs up he makes another, thumbs down he doesn't...

Bryson DeChambeau is finishing up on the 18th hole. He's on the green in three, and facing a speedy birdie putt down the slope.

Not a lot of time given to it. I think Bryson just wants to get out of Torrey Pines right now.

It's a six-over-par 77 to finish.

He misses.

It was never in, always off to the right.

A bogey - and Jon Rahm's lead doubles to two, with one hole remaining.

That changes everything. If Oosthuizen can rescue a par here, then a birdie on the par five 18th forces a play-off...

Hold the phone.

What a shot from the drop.

Right on to the green - a chance for par save from maybe 12 feet.

Here are the birdies that Jon Rahm holed on the 17th and 18th holes that sent him top of the leaderboard and seemingly set to win his first major...

Wonder what Jon Rahm is feeling right now.

No sportsman likes to see another make a mistake like the one Louis Oosthuizen just made.

But it's a mistake that could hand Rahm his first Major title, at the relatively tender age of 26.

Rory McIlroy misses a seven-foot putt for birdie on the 17th. A shrug of the shoulders as he hands his putter back to Harry Diamond, his caddie.

There's a hint of a smile. It's been good to see the Northern Irishman in the thick of things on the final day of a major and but for that unfortunate lie in the bunker on 12 that led to a double bogey...

Oh no. What a way to lose it. Potentially.

Louis Oosthuizen is well to the left off the 17th tee - so much so that the ball flies into the vegetation outside the course's red lines.

That will be a penalty shot. The South African will need a miracle not to drop a shot here.

Louis Oosthuizen is exactly where he began the day, on five under par.

The trouble for him is that Jon Rahm has carded a 67 to move one shot ahead.

He gets it. Lovely putt, kept straight. No twitching there.

Two holes to go. Jon Rahm still leads by one.

Bryson DeChambeau cuts a disconsolate figure as he trudges off the par-four 17th green after signing for an 8 (EIGHT!)

I'm trying to work out what happened. He certainly took a penalty drop after driving into the rough. He then found more greenside rough and chipped across to the other side and then had a couple more swipes.

Anyway, safe to say, it was a disastrous hole and plummets him down the leaderboard.

Now then, a big putt for Louis. Got to be 35 feet...

Oh dear, he doesn't judge it well at all, it breaks far too early.

A bum-twitcher for par now from six or seven feet.

Amid all that chaos surrounding Jon Rahm on the 18th, Rory McIlroy was trying to get up and down from a greenside bunker on the par-three 16th to keep his faint hopes alive.

Alas, he missed a par putt from a dozen feet. The wait to break the major duck will go to next month's Open Championship at Royal St. George's...