Newcastle United pulled off a 1-0 win over Chelsea to reach the FA Cup quarter-finals on Sunday after the English Premier League leaders finished a pulsating tie with only nine men.
A tactical gamble by Chelsea coach Jose Mourinho turned the game, his decision to make all three substitutions at halftime backfiring in spectacular fashion when wingback Wayne Bridge was carried off on a stretcher just minutes after the re-start.
That left Chelsea with 10 men and struggling to cancel out a superb header by Newcastle's Dutch striker Patrick Kluivert after only four minutes at St James' Park.
Mourinho, who was also paying the price for starting with a second-string side before next week's Champions League knockout tie at Barcelona, saw all hope fade in stoppage time when goalkeeper Carlo Cudicini was red-carded for felling Shola Ameobi.
Nottingham Forest came back to draw 1-1 at Tottenham Hotspur and Burnley drew 0-0 with Blackburn Rovers in a moral victory for second division clubs over Premier League sides in Sunday's other fifth round ties.
Holders Manchester United reached Monday's draw with a 2-0 win at Everton on Saturday but Arsenal, held 1-1 by second division Sheffield United at Highbury, were among eight clubs facing replays.
The place to be for thrills on Sunday was Tyneside, where Newcastle battled to a famous victory over a club who have been dominating English football this season and have a League Cup final against Liverpool next Sunday.
CHELSEA RESTING
Mourinho played a major part in what happened, sparing nearly all his first-team regulars in his bid to match last season's Champions League triumph with Porto.
Mourinho told Sky Sports News: "We showed with the team we started with that we have other competitions in front of the FA Cup. But we came here to win.
"Sometimes you are proud of your team because you win and sometimes you lose like today and you're still very proud...I think they were magnificent."
Newcastle boss Graeme Souness, whose side were following up a midweek UEFA Cup third round win at Dutch club Heerenveen, said: "It was a good result against an excellent team. I'm sure everyone will get a lift from this."
Kluivert was quick to exploit Mourinho's team selection, though Chelsea's Serbia and Montenegro striker Mateja Kezman was unlucky not to equalise when he hit the bar before the end of the first half.
The turning point came when the Portuguese coach threw on winger Damien Duff, striker Eidur Gudjohnsen and attacking midfielder Frank Lampard for the second half.
Bridge was carried off with a suspected broken ankle within five minutes and Chelsea were in trouble well before Cudicini was shown the red card which will cost him a suspension for the League Cup final.
Newcastle skipper Alan Shearer told Sky Sports News: "Jose gambled at halftime and it didn't really pay off."
Victory was assured at the very end by Cudicini's red card as Newcastle kept alive their dreams of a first FA Cup final success in 50 years.
Earlier on Sunday, a goalkeeping howler by Forest's Colin Doyle allowed Tottenham's England striker Jermain Defoe to score with a free kick just before the break at White Hart Lane.
But Forest matched their wealthier opponents and were rewarded as striker Gareth Taylor equalised from close range in the 56th minute to earn a replay at the City Ground on March 2.
The Lancashire derby at Turf Moor was high on passion but low on quality, with Rovers having slightly the better of the few chances.
The real upsets came on Saturday, however, when second division Leicester City beat top flight Charlton Athletic 2-1 at The Valley and Southampton were held to a 2-2 home draw by third division Brentford after squandering a two-goal lead.
Bolton Wanderers overcame visitors Fulham 1-0 in an all-Premier League tie.