And while United contemplate another Wembley final,
City will have to shelve plans to take over as the No1 club in the
city.
Goals from Paul
Scholes and Michael Carrick put United 3-2 ahead on
aggregate.
First-leg hero Carlos Tevez looked to have forced
extra-time with a 76th-minute reply.
But Rooney popped up in the second minute of injury
time to break City's hearts.
United keeper Edwin van Der Sar was the slightly busier
keeper in a first-half which although had a feisty edge to it,
failed to really spark.
Van der Sar made routine saves from headers by Craig
Bellamy and Carlos Tevez.
At the other end, Shay Given had to be alert to get
down to a Ryan Giggs drive after a neat United move.
Perhaps the major talking point was whether Rio
Ferdinand illegally pushed Tevez off the ball as the Argie striker
surged into the box.
The second half got off to a storming start as Micah
Richards ran from halfway before forcing Van Der Sar into a superb
fingertip save from his left-footed curler. From the corner, Giggs
failed to clear but Bellamy's half-volley only found the midriff of
Van der sar.
Bellamy was then subjected to a torrent of abuse as he
went to take a corner. And the incident turned ugly when bottles
were thrown at the Welshman before he was hit on the head by a
coin.
Play continued and immediately United broke through
Wayne Rooney. He played in Giggs with a glorious 50-yard pass, with
the Welshman's first touch equally devastating. He was forced wide
and Nani then looked to have wasted the chance before Michael
Carrick touched the ball to Scholes who hammered home from just
inside the box.
Richard saw a shot diverted over by Jonny Evans but
United took the lead on 71 minutes.
HEAD BOY ... Wayne Rooney pounces to nod home
his last-gasp winner
Nani's cross found Fletcher and although he
could not get a shot away, he kept his cool to touch the ball to
Carrick who passed the ball into the net.
Rooney should have killed the tie two minutes later but
he somehow stabbed wide from inside the six-yard box.
And City took advantage as they quickly got back on
level terms, with Tevez getting ahead of Ferdinand to cleverly
flick home Bellamy's curling centre.
Carrick was left cursing himself after dragging a shot
wide from eight yards having seen his first effort blocked.
But the real drama was still to come as first
Fletcher's header was kept out by Given before Rooney stole the
glory by popping up to head home Giggs' centre.
