Liverpool remain on course for a cup double this season after Dirk Kuyt's late winner secured a 2-1 victory in their FA Cup fourth round clash with Manchester United at Anfield.
Daniel Agger's opener was cancelled out by Park Ji-Sung shortly before half-time, but substitute Kuyt hammered the winner in the 88th minute to avoid a replay at Old Trafford.
In the week that Liverpool secured a return to Wembley for the first time in 16 years with a Carling Cup triumph over Manchester City, Kenny Dalglish's men secured an historic cup win over bitter rivals United.
Patrice Evra, returning to Anfield for the first time since his race row with Luis Suarez in October, was handed the captain's armband by Sir Alex Ferguson, who left an injured Wayne Rooney out of his squad.
With Danny Welbeck named as the lone striker, it was Antonio Valencia who came closest to breaking the deadlock, the winger evading the challenge of Maxi Rodriguez before drilling a low strike which beat Pepe Reina but rebounded off the keeper's right post.
But when De Gea failed to deal with Steven Gerrard's inswinging corner, Agger rose highest to plant a firm header into the net. Their lead lasted 18 minutes, and after Rafael dispossessed Jose Enrique on the right, his cross was met by Park, who hammered a low strike beyond Reina.
Andy Carroll had the chance to regain Liverpool's advantage in the second half when Chris Smalling slipped attempting to clear under pressure in the penalty area. The former Newcastle striker swivelled, but his strike was well blocked.
Moments later, Welbeck was through on goal after a superb through ball from Michael Carrick, knocking the ball past the onrushing Reina, but Martin Skrtel was on hand to clear.
When Stewart Downing was fouled by Rafael, Gerrard stepped up, but his free-kick was well saved by De Gea. Carrick saw his low strike edge past the left post, while Welbeck squandered two late chances.
The introduction of Kuyt, Charlie Adam and then Craig Bellamy energised Liverpool, and when Carroll's header released Kuyt from Reina's long ball, the Netherlands international lashed an emphatic finish with his first touch of the ball. He had the chance to grab a second, but he fired wide as Liverpool hung on to claim a memorable victory.
Gus Poyet once again ended the FA Cup hopes of Newcastle as Championship side Brighton pulled off a shock 1-0 win.
As a Chelsea player in 2000, Poyet's two goals knocked Newcastle out in the semi-final at Wembley as the Blues went on to lift the trophy. And 12 years later the Brighton manager masterminded a famous win for his side as Will Buckley's shot, deflected into his own net by Mike Williamson, sent the Magpies packing.
Brighton had already knocked Sunderland out of the Carling Cup this season at their new Amex Stadium, and thanks to Buckley's lung-busting run and shot 15 minutes from time, they secured a north-east double scalp.
Juan Mata's penalty secured Chelsea's place in the fifth round with a 1-0 win against West London rivals Queens Park Rangers at Loftus Road.
With all the attention on John Terry and Anton Ferdinand before kick-off, the FA cancelled pre-match handshakes in a bid to avoid any controversy in the midst of their alleged race row.
With the game goalless after an hour it looked like QPR may secure a replay at Stamford Bridge, only for Mata to clinch the win, albeit in controversial circumstances.
Daniel Sturridge won the penalty for Chelsea, but referee Mike Dean was met by a furious reaction from QPR players, who felt the striker had dived after a soft challenge from Clint Hill
Chelsea progressed, but their afternoon was soured by the sight of Ramires leaving the field on a stretcher with what appeared a serious knee injury.
Matt Tubbs was the hero once again for Crawley Town as the League Two side reached the FA Cup fifth round for the second successive season with a 1-0 win over Hull City.
Tubbs, who scored against Manchester United in the fifth round last season, netted the only goal of the game shortly before the hour mark as Nicky Barmby's Tigers fell short at the KC Stadium. Tubbs scored his 18th goal of the season, beating Vito Mannone from the left. Hull threw everything at the visitors, but they were left exposed at the back and on-loan Arsenal striker Sanchez Watt hit the woodwork for Crawley.
Chris Eagles scored the winner as Bolton Wanderers came from behind to beat Premier League rivals Swansea City 2-1. Swansea dominated possession in midfield, but keeper Gerhard Tremmel made a string of early saves to keep the Trotters at bay.
Luke Moore fired the Swans ahead with an exquisite chip over Adam Bogdan, but the visitors' lead lasted just three minutes as Darren Pratley scored against his former club, meeting Martin Petrov's cross to head the equaliser in first-half stoppage time. And Eagles grabbed the victory for Bolton, lashing home from close range after Tremmel spilled Petrov's effort.
In the day's fourth all-Premier League encounter, Simeon Jackson grabbed a late winner as Norwich City beat West Bromwich Albion 2-1 at The Hawthorns. Marc-Antoine Fortune thought he had earned a replay for the Baggies after his 54th-minute strike cancelled out Grant Holt's opener, but Jackson snatched victory five minutes from time.
Holt scored his fifth goal in as many FA Cup appearances to put the Canaries ahead, but Fortune, poked home from Jerome Thomas' pull back from the left to equalise, before Jackson pounced on a mistake by Craig Dawson to seal a dramatic victory.
Last year's finalists Stoke City booked their place in the last-16 with a 2-0 win over Derby County at Pride Park. Cameron Jerome scored his fourth goal in five games to give the Potters an early lead, the former Birmingham striker volleying home after Peter Crouch flicked a corner on at the near post.
Tony Pulis would have wanted his side to put the result to bed, but they had to wait until the 81st minute to score a second against their Championship opponents, Robert Huth's tame effort beating Frankie Fielding to squirm over the line.
Two goals from Jermaine Beckford ended Swindon Town's FA Cup dream as they fell 2-0 at the hands of Leicester City. The Foxes, who toppled Championship high-flyers Southampton on Monday, grabbed an early lead courtesy of the in-form Beckford, who swept in from close range after a tantalising cross from captain Matt Mills.
The former Everton winger, who scored a hat-trick third in Leicester's fourth-round win over Nottingham Forest, sealed the victory with his second against Paolo Di Canio's brave Swindon side, who were on top for much of the game.
Millwall striker Darius Henderson earned a replay after his late strike secured a 1-1 draw against Championship high-fliers Southampton at the New Den. Henderson's late strike four minutes from time frustrated the visitors, who had taken the lead courtesy of top scorer Rickie Lambert, returning from suspension to nod home Dan Harding's cross after half-an-hour.
Adam Rooney scored a brace as Birmingham City rolled into the fifth round with a 4-0 win over Sheffield United at Bramall Lane. Despite a bright start by the Blades, the Blues grabbed the lead through Nathan Redmond, who collected Jordan Mutch's pass and drilled a low strike past Steve Simonsen. Rooney doubled the visitors' lead after 38 minutes before Wade Elliot's deflected effort put Chris Hughton's side firmly on course for victory. And Rooney put the icing on the cake, slotting home after a well-worked move by Birmingham.
Kevin Phillips earned a replay for Blackpool, his late penalty earning a 1-1 draw against Sheffield Wednesday at Bloomfield Road. Clinton Morrison thought he had done enough to seal victory for the Owls with his 52nd-minute strike, but after Danny Batth brought down Gary Taylor-Fletcher in stoppage time, Phillips stepped up to fire in the equaliser from the spot.
Meanwhile at Broadhall Way, Damion Stewart's own goal secured Stevenage's place in the fifth round with a 1-0 win over League One rivals Notts County.