England international Wilfried Zaha proved the difference as Crystal Palace beat Watford 1-0 after extra-time to seal promotion to the Premier League.
The Championship Final was a tight affair throughout but Palace were the better side overall and deserved their victory.
And that win was sealed when Zaha, who was playing his last game for Palace before moving to Manchester United next season, won a penalty for a foul by Marco Cassetti.
The 20-year-old will play for England Under-21s in this summer's European Championships, but this was the perfect way to sign off from his boyhood club.
Zaha officially joined the Premier League champions in January but was loaned back to Palace for the remainder of the season – and having scored both goals in their semi-final win over Brighton, this was the ideal way to say goodbye.
And Wembley was again packed to the rafters just two days after the Champions League Final between Bayern Munich and Borussia Dortmund.
But the opening period was a cagey affair with few chances, but the game became stretched after the break.
Both managers were well aware of the importance of the game, which is estimated to be worth around £120m.
So it was perhaps no surprise that neither side were committing too many men forward in an opening period that was enlivened by a series of fine runs from Zaha down Palace's right.
But that changed after the interval as the game really came to life.
Watford had two half-chances through Alex Geijo and Troy Deeney but then Palace had three superb opportunities within 90 seconds.
The first fell to Stuart O'Keefe after Zaha had played him in, but the midfielder was denied by Manuel Almunia. And the Spaniard then made an even better save from Aaron Wilbraham after the ball had reached the striker just three yards from goal.
Danny Gabbidon was unable to turn a loose ball in at the far post from the resulting corner, and Owen Garvan was incredibly unfortunate when his superb spin and volley was straight at Almunia.
The next chance went to Wilbraham as Zaha played him in, but the striker was again denied by Almunia's out-stretched boot.
And when the former Arsenal goalkeeper saved Mile Jedinak's header to ensure the game went to extra-time Palace must have been fearing it wasn't to be their day.
Watford created their best chance two minutes into the extra period, though, as Julian Speroni somehow stopped Troy Deeney from putting Almen Abdi's cross into the gaping net.
Cristian Batocchio's long-range effort was smothered by Speroni shortly after as Watford started to turn the tide back in their favour – but the decisive moment came seconds before half-time in extra-time.
Zaha had seemed the player most likely to make the breakthrough all afternoon and he made the difference as he lured Marco Cassetti into a rash challenge inside the box – and when contact was made, referee Martin Atkinson had no choice but to point to the spot.
Phillips immediately grabbed the ball and his penalty was superb, hit high into the top corner to give Almunia no chance.
Watford weren't giving up, though, and Cristian Battocchio turned superbly in the box and poked the ball past Speroni only to be denied by Joel Ward's block on the line.
And a minute later Atkinson blew his whistle to ensure Palace return to the Premier League for the first time since 2005.
