Entering the fray in the fifth over of the morning after being promoted back up the order, Watson dominated the action with his 176, which included 25 fours and a six.
Having failed to ruffle many feathers in the first three Tests as an opener, he was dropped down the order to No 6 at Durham and duly made his first half-century of the series in the first innings there.
And given the opportunity to make a serious contribution in London he delivered for captain Michael Clarke with big runs, taking particular delight in making life difficult for Chris Woakes and Simon Kerrigan on their Test debuts.
Both were given their chance before lunch and Watson was quick to make his point after surviving an lbw shout against James Anderson, crashing six boundaries off each bowler in making 80 out of his side's score of 112-1 at the interval.
The Queenslander had to take on a different role in the afternoon as both Chris Rogers and Michael Clarke fell, threatening to plunge the tourists into a crisis.
But, aided by an increasingly confident Steven Smith, Watson marched on after receiving a life when on 104, Anderson inducing some extra lift from an otherwise lifeless pitch to catch the edge only for a diving Alastair Cook to grass the opportunity at slip.
Broad-shouldered Watson, struck just under helmet by a Stuart Broad bouncer in the 90s, was otherwise imperious though as he patiently waited for the right ball, taking advantage of anything short of a length.
Another life came on 166 when he was adjudged lbw by umpire Aleem Dar to a short one that kept low, however a review showed the ball was going over the stumps by a fair margin.
Only a fine catch in the deep by Kevin Pietersen spoiled Watson's day and this innings alone has gone a long way to cementing his position at No 3 as the teams look ahead to the next series Down Under this coming winter. It will surely give England pause for thought.