Paul Casey looks pumped on the par three sixth. And why not?

His tee shot skirts inside the fringe of the green down the left and he then rolls in a very testing putt for another birdie. He's two strokes clear. So far so good for the Englishman.

-7 Casey (15*)

-5 Simpson (17*)

-4 Westwood (16), Schauffele (14), Woods (13*)

-3 Matsuyama (7*), Kuchar (15), Rahm (16*), Oosthuizen (16*), Kokrak (14), Day (14)

Selected others:

-2 Reed (15*), Finau (15*),

-1 Cabrera Bello (11), Woodland (13*)

E DeChambeau (16*), Stenson (14)

A nice putt from Woods, with his stance hampered slightly by the bunker. No nonsense - four feet to the hole.

Image source, Getty Images

DeChambeau doesn't get enough weight on his chip and it only reaches the fringes. He reaches for his putter - off the longer cut, up and then back down the slope to save par? Not a bad effort, but it'll be a dropped shot for the US Open champion. Back to level for his round.

Jon Rahm has work on too. And he bogeys. Back to three under.

Oosthuizen makes par.

Jamie Donaldson
Ryder Cup 2014 winner for BBC Radio 5 live

It's always best to go out early, as the greens are perfect, but obviously the later players today are getting the better weather, but I still think it's better to be out at the start.

The champion has 216 yards to the hole - DeChambeau used a wedge, while it's a short iron for Woods.

The ball looks set for the bunker on the left but escapes the pit. Awkward stance for the putt/chip though. Tight against the cushion in snooker.

The par-five 15th is historically eyed as a birdie opportunity by most players but it's not to be for Lee Westwood, who takes three to mop up after well over clubbing his second.

Iain Carter
Radio 5 live commentator

The ball is just sticking as soon as it lands on the fairway. It could mean mud balls, which means control could be tricky.

Woods finds the fifth-hole fairway with another cautious tee-shot, but the tactic is working well for him. You wouldn't dispute tactics with the five-time champion, would you?

DeChambeau is in the trees again. He's spent a fair bit of time in there today. The American manages to hack out but flies it beyond the green and into a fierce looking bunker.

"This is a huge blow," explains sports writer Scott Michaux, formerly of the Augusta Chronicle. "It's a massive economic engine for the community in so many different areas."

The tournament provides an annual windfall said to be worth $100m (£76m) for the Augusta economy. More than 200,000 people pass though the city during Masters week, doubling its population.

Hotels hike up their rates to sometimes six times the average price, locals move out of town for the week to rent their properties to patrons and some nearby golf clubs sell tee times for $1,000.

"River Club, Champions Retreat, Forest Hills, Akin GC, Palmetto GC in South Carolina, they make an enormous amount of money that week, not just for the golf, but some cater and host social events in the evening and rent out their clubhouse," says Michaux.

"Then you have the people who rent their homes, they count on that income every year - home-renters, caterers, they refer to the Masters as either a second Christmas or the 13th month of the economic year, that's how big it is to the community.

"Every little industry you think of is affected by this in Augusta. You can't replace not having it for a season. Augusta National is fine, they can go years without having fans and still be in great shape economically, but the community is hurt badly by it."

Crikey. What is Lee Westwood doing? Has he had an energy bar or has he just had too much spinach?

Looks like he has flown through the back on 15 by a good 60 yards or so.

He just needs to hold himself together here and he could well be posting a very decent first-round score. A tricky downhill chip back on awaits.

Yet another Woods birdie putt drifts past the hole.

It's still excellent golf from the champion, who has shown little form since the restart.

He has five to play - we go to the par-four fifth.

Iain Carter
Radio 5 live commentator

One of the distinguishing features with this Masters is that they are using two tees, due to the lack of daylight. They do this at lots of other tournaments but never usually at Augusta, as the Masters has an invitational field that is usually fewer than 100 players.

Paul Casey wallops his tee shot away on Magnolia, an uphill dogleg that veers off left to a sloping green.

Just for reference he's a good 50 yards back on where Bryson DeChambeau landed his tee shot on this hole.

A short while ago, Paul Casey played the par-five second in three shots to pick up an eagle. And this is how he did it...

Louis Oosthuizen, runner-up at Augusta in 2012, is two off Paul Casey's lead and without a blemish on his card today.

The South African runs a long birdie putt at the par-three sixth towards the pin but it doesn't quite have the legs.

That's some way short in the end... tricky for Louis this, and he does drop for the first time today. A three-putt bogey for Oosthuizen. He slips to three under.

Jon Rahm, on four under, makes par, while Bryson DeChambeau is also in for par after seeing his birdie putt break short and early.

Woods seven iron.

Eight feet shy of the fourth pin on Flowering Crab Apple.

Remarkable.

Ouch!

Woods' putt drifts past the right of the third hole - the pace was perfect.

Another par and his card remains unblemished.

Another birdie chance for Paul Casey on the par-three fourth, which is his 13th hole of the day.

That one needed a little more gas though. Another par.