League Two side Rochdale reached the FA Cup fourth round for the first time in 11 years with a deserved win against Leeds United at Spotland.
Scott Hogan put the hosts ahead when he planted Peter Vincenti's teasing right-wing cross past Leeds goalkeeper Paddy Kenny seconds before half-time.
The Championship side's fate was sealed when man-of-the-match Ian Henderson superbly volleyed into the top corner.
Matt Smith's first-half header was cleared off the Dale line for Leeds.
That was the closest the visitors came to scoring and Scotland striker Ross McCormack also sent a shot over the crossbar after the break, but Brian McDermott's side failed to test Dale keeper Josh Lillis.
Leeds have a rich pedigree in the FA Cup, having won the 1972 final and finishing runners-up on another three occasions in the 1960s and 1970s.
In contrast, Rochdale have never progressed past the fifth round of the competition - but the home side were never overawed by history, nor a side who are 45 places above them in the league ladder.
Hogan, who returned to Rochdale in the summer after brief spells at non-league sides Halifax and Hyde, was a constant menace to Leeds' stretched backline with his pace and movement.
The 21-year-old was twice denied by Kenny before his goal, shooting straight at the ex-Republic of Ireland international after previously being denied by a last-ditch sliding tackle.
Leeds, who have slipped to eighth in the Championship after failing to win in their last four games, lacked rhythm in the final third and were often put on the back foot by rapid Rochdale counter attacks.
FA Cup fourth round draw
Sunday, 5 January 2014
Cousins Martin and Paul Allen, who both played for West Ham, will make the draw after the Hammers face Nottingham Forest.
Fourth round dates:
Ties to be played over the weekend of 25 and 26 January 2014
So it was unsurprising when Hogan headed in the opening goal with virtually the final touch of an entertaining first half.
Leeds continued to probe after the break but, to the frustration of over 3,500 travelling fans, were unable to get a meaningful shot on target.
The Yorkshire club have become FA Cup giant-killers themselves since being relegated from the Premier League in 2004, embarrassing the likes of Manchester United, Arsenal and Tottenham in recent seasons.
But as the game moved into the closing stages it only looked as they would be on the receiving end of an upset on this occasion.
Rochdale continued to push for a second goal, with Vincenti and Hogan firing wide in quick succession before Kenny acrobatically tipped over another Vincenti effort.
But it duly arrived when Vincenti secured Dale's first victory against Leeds in three attempts - sparking jubilant scenes inside Spotland at the final whistle.
VIEW FROM THE DRESSING ROOM
Keith Hill audio on Rochdale's win over Leeds:
"it's a tremendous win but I think there was doom and gloom when we played Torquay away and there was an expectation for us to maybe go out of the competition, like we did do against Southend when I was previously here. A long trip with no reward would have cost the club a fortune, but today we got our reward.
"We had a game plan, we had trivial banter I suppose before the game with the Chief Exec, the Chairman and one or two of the board members on team selection. I think everyone was surprised with the team today but we had a game plan and the game plan worked.
"I'm really pleased for the players because I do believe that more than one or two of the players are more than capable of playing above League Two standard. I feel as though the team can, but we have to be able to get promoted from this league."
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