Despite Manchester United's fine victory over Tottenham last weekend, it was expected that Red Devils chief Louis van Gaal would replace Spanish international Juan Mata with club record signing Angel di Maria for today's crunch showdown with Liverpool.
He didn't - Di Maria took his place on the bench, and Mata stole the show on Merseyside.
Of course, many will suggest that it was the obvious choice...why change a winning team? Why make changes after the club's best performance of the season?
But, as a tactical battle, it seemed appropriate that Di Maria would would slot into the starting XI as he would be able to offer the Red Devils pace down the flanks, and help them hit Liverpool on the break.
Van Gaal, though, stuck to his guns and selected Mata, who had by some way his best performance in the red shirt of United.
His second goal - the eventual match winner - was something of complete genius: with incredible technique, he steered the ball past Simon Mignolet with a quite brilliant volley on the half-turn.
In fact, his first - the opening goal of the game - wasn't bad as the Red Devils countered their rivals in style. It was a fine goal, but will rightly be overshadowed by his match-winning second of the day.
The goals, of course, are crucial, but Mata must also be commended on his all-round performance. In truth, it was all pretty clear to see why Chelsea boss Jose Mourinho opted to get rid of the extremely talented playmaker.
Clearly, for the way Mourinho wanted to play the game, Mata just didn't offer enough defensively; he was recognised as a luxury player.
And, to an extent, Van Gaal may well have similar thoughts; there have been times when the Dutchman has left Mata out of the side, often a tactical decision.
Today, though, Mata finally announced himself as a Manchester United player. He proved that he is not a defensive liability, while proving that he is classy in everything he does.
Yes, he is a luxury, but based on today's performance, he is also a team player. He was up for the occasion; he was up for the battle.
There's no doubt about it, the duo of Mata and Antonio Valencia down the right hand flank wouldn't have filled supporters with confidence when the club were on the back foot, but United looked assured all day long.
The likes of Adam Lallana, who was shipped off at half-time, and Raheem Sterling barely got a look, especially down the right.
It's pretty obvious that Manchester United fans have fallen in love with Mata - he has just made himself even more lovable.
Manchester United fans: How good was Mata today? Do you now think your club will qualify for next year's Champions League? Have your say in the comments section below!