Bubba ain't done yet though, knocking in a birdie two himself. Not as spectacular as the young pretender but just as effective.
By the way, I'm sorry to report that Westwood is now three over for the day after six. Rose is two over after seven and Poulter one over after nine. Augusta has seemingly got a taste for British meat at the moment.
Kuchar & Blixt both evens after four...
It appears Poulter and Fowler are both wearing the same bright orange golf shoes. They must be mortified...
McIlroy drops one on 13 and Mission Improbable is officially over.
Wales' Jamie Donaldson having a cracking day. He's three under for the day now and has dragged himself back up to evens for the tournament. *respect*
After all that early excitement, it's all gone a touch quite at the top of the leader board. The calm before the gathering storm? I would say so.
Hang on, something significant has just happened. The boy wonder, aka Jordan Spieth, has only gone and dropped a shot on 5 and that lovely, comfy two-shot cushion he was enjoying disappears.
It's a good day too for Stephen Gallacher. The Scot is two under for the day with two to play.
Rose birdies the 9th and he's back to level par for Sunday and one under overall.
The battle royale continues. Bubba and Spieth both birdie six and the lead pair extricate themselves from the pack.
Kuchar & Blixt yet to fire on all cylinders. Par after six on this course is respectable but you need more than that to win the Masters.
Blixt blinks, dropping a shot on the 7th and he falls four behind Spieth. It's not a disaster but it's not yet happening for the Swede on day four.
Americans dominating the Masters now. Chances of a first European win since Jose Maria in 1999 appear to be fading fast.
Spieth makes another birdie. This time it comes courtesy of a perfectly weighted putt to go eight under. That's his fourth birdie already today.
Watson can only muster a par on seven and the lead stretches back to two shots.
It's the classic sporting contest. The older, more experienced head of Watson versus the gloriously uncluttered mind of the youthful Spieth.
Couples and Bjorn drop back with dropped shots...
It is extremely tempting to now view the 2014 Master as Spieth and Watson versus the rest. Kuchar wouls surely disagree of course but there is a sense of gladitorial inevitability about it.
Hold that thought. Blixt birdies eight and he joins Kuchar at four under for the tournament. The leading non-American in the field might yet have a say in proceedings.
Breeze picking up at Augusta and may yet have a part to play in the next hour-and-a-half.
Watson produces a sublime chip on the 8th, leaves it a few feet short and looks nailed on a for a pressure-inducing birdie. Pressure on Spieth that is.
The pressure tells. Spieth misses a shortish par putt - his first three putt of the tournament - to drop a shot. Bubba sinks his birdie effort and in the blink of an over agitated eye, the two American combatants are suddenly level on seven under.
Couples double bogeys the 11th and we can safely say that Fred will not be donning the Green Jacket now.
Kuchar bogeys nine to drop back to three under. He's out in one over for the day and has nine holes left to make an impression. Blixt pars to remain three off the leaders.
Advantage Bubba on the 9th. Spieth is short with his second and rolls agonisingly down the hill, Watson is level and it's even money he's going to sneak a shot ahead of his rival when this hole is done and dusted.