This is exhausting.

He has us up, he has us down. It's a third birdie for Rory McIlroy after an opening six holes that have featured two bogeys too.

The four-time major winner looks cool as anything as he bangs the 17ft birdie putt in. He's three off the top spots.

Will Zalatoris is all over the place at the minute. The American goes well right off the tee and elects to have a dig at the green from the longer stuff to no avail, seeing his ball come up well short and possibly skip into the sand down the right.

Matt Fitzpatrick, playing from the left of the fairway, produces a sublime shot to nip into eight feet.

Can he knock this in for a birdie and share of the lead? Of course he can.

While Fitzy is heading in the right direction, the same cannot be said of his playing partner, Zalatoris ends up with a long putt to save par and coughs up another shot.

"Let's go!" comes the Boston cry as Rory McIlroy steps up for his tee shot on the par-three sixth.

He's had two bogeys there this week, but things are looking up today. He lands his ball on the ledge and it stays there to set up a birdie chance.

There are a couple of Americans making their way up the leaderboard.

We recently mentioned Denny McCarthy and Nick Hardy has joined him on two under as well now after back-to-back birdies on the fourth and fifth.

It's three birdies in four holes as Scheffler strikes the front on five under!

He's got 136 to the flag on four, and hits it about 135 but sadly it's got plenty of action on and spins back a good few yards.

That's no problem for Scheffler's red-hot putter though as he drains a 24-footer to go out in front on his own.

It's met with Scheffler's traditional low-key celebration, just a half-hearted fist bump with is caddie.

Birdie chance for Jon Rahm at the third. The Spaniard is playing granite golf and finds the centre right of the third green but can't nail his putt.

Pars sometimes win prizes mind. Just ask Sir Nick Faldo.

Keegan Bradley is having one mind. A third straight bogey after a missed three footer.

Quite why the American thought he needed to rattle his par putt so hard is beyond me.

McIlroy gives his ball a good whack to try and get it up the hill but it's way too much.

He swipes past the mark, has 15ft to go for par and... misses!

The US Open is a rollercoaster for Rory. So far: Birdie, par, bogey, birdie, bogey. You can't call him boring.

McIlroy got lucky with his lie after a dodgy tee shot on the fifth.

He manages to avoid the deep grass and you might think his second shot onto the green is a decent one.

But the fans know better. They shout "stay" as the ball cheekily starts creeping its way towards the front of the green and just keeps on rolling...

A lot of work to do to get it down in four for a par.

Will Zalatoris finds the false front to the second green off the second tee. A long uphill putt incoming, which he pushes well past. It'll take a good putt to save par from there.

Matt Fitzpatrick coming up now from 20 feet or so. This is looking good, this is looking good, oh my it misses right by an inch. So close for the Englishman, who watches on as Zalatoris misses on the the return trip.

American Denny McCarthy's previous best US Open result was tied for 42nd in 2015.

He's looking like he might trump that this year.

The 29-year-old has just birdied the fourth and fifth holes after also gaining a shot on the first. He's two off the leaders.

From the highest highs to the lowest lows...

McIlroy's tee shot on the fifth goes way left. Is it in the deep grass? Is it among the fans? We'll soon find out.

Speaking of fans, there are plenty of Irish ones in the Boston area and many of them have been enjoying McIlroy so far.

Image source, Getty Images

There's no hat-trick of birdies for Scheffler as he has to settle for par on the third, but Adam Hadwin does manage to land a bomb from downtown Boston - but sadly it's just for a par.

Wow.

Looking at Rory McIlroy's birdie putt, many would want to play it safe, get close and take a par.

But this is the final day of the US Open. And he's looking for a first major win in eight years.

With that in mind, McIlroy goes straight at it and the ball curls its way into the cup. He's two off the leaders again.

Jon Rahm has not quite found his range yet and comes up a little short at the par-three second but he retrieves the situation by wafting another chip into around five feet and rolling in the putt.

Keegan Bradley finds the back right of the green and has a birdie putt to regain his dropped shot from the first. Oohh, that's close from the American who prods his ball past by millimetres.

A simple five footer for par...oh he's missed that as well. Back-to-back bogeys!

McIlroy hasn't quite covered enough of those 153 yards.

He goes a tad short and, to rub salt in the wound, the ball rolls slightly backwards down the green too.

It will be a tricky 20ft putt for the birdie.

Ok, everything is OK.

Rory McIlroy follows up his bogey with another solid tee shot, which lands in the middle of the fairway. He's got 153 yards left to cover on the par four.

Birdie putt incoming for Matt Fitzpatrick, who whips his second into the left centre of the green.

Not that close with the putt, as it veers right, but he should make four here. He does.

Will Zalatoris finds the rough with his second but then scrambles a par, with an outrageous third to three feet.

Solid start.

It's the hope that kills you...

After the thrill of an opening birdie, a trip to the rough on the third leaves Rory McIlroy too much to do with his putter.

He slides the par attempt left of the hole and can only bat in for a bogey. Back where he started.

The bad vibes have rub off on American Sam Burns too, who also drops a shot.

Scottie Scheffler makes a storming birdie-birdie start and he joins the leaders on four under.

It's a decent tee shot on the par-three second and a fine putt from right on the edge of the green, it does a 360 around the hole but drops in to put Scheffler level with Zalatoris and Fitzpatrick.

An ominous start from the world number one.