The biggest shock of Saturday's FA Cup third round matches came at Eastlands where Championship strugglers Nottingham Forest knocked out Manchester City with a memorable 0-3 win.
Nathan Tyson stunned the Eastlands with a 38th minute volley to open the scoring and Robert Earnshaw's 42nd minute goal ensured City trudged off to resounding boos at half-time.
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Jo came on in the second half as City desperately chased goals but it was Forest who grabbed another as substitute Joe Garner's 75th minute strike condemned City to a humiliating defeat which is sure to increase the pressure on manager Mark Hughes.
Elsewhere Chelsea were stunned by an injury-time Southend equaliser which set up a mouth-watering replay for the Shrimpers.
Salomon Kalou's 31st minute header looked as if it was going to be enough for the Blues, but Peter Clarke's header at the death ensured a trip to Essex for Luiz Felipe Scolari's men.
Another big upset came at Victoria Park where League One Hartlepool knocked Premier League strugglers Stoke City out of the competition.
Goals from Michael Nelson and David Foley put the League One side in to the hat for the fourth round draw leaving the Potters to concentrate on the battle for Premier League survival.
Cup holders Portsmouth were held to a disappointing 0-0 at Fratton Park against Bristol City with Peter Crouch going close for the home side, but Tony Adams men will have to travel to the West Country for a tricky replay.
Arsenal captain Robin Van Persie headed a 47th minute goal against Plymouth before a David Gray own goal three minutes later appeared to have killed the tie.
Plymouth responded swiftly though and a Karl Duguid goal gave them renewed hope but Van Persie's 85th minute goal killed off any hopes of a late comeback.
In Saturday's late game, Liverpool survived a difficult trip to Deepdale to progress to the next round after a keenly fought tie with Preston.
Albert Riera and a late Fernando Torres goal (selflessly set up by Steven Gerrard) were the difference between the two sides in a match which saw Preston have an equaliser chalked off.
Kenwyne Jones headed Sunderland in to the lead against Bolton in the all-Premier League tie at the Stadium of Light and Djibril Cisse got the second in the 67th minute.
Ebi Smolarek's first goal for Bolton put them back in contention but the Black Cats held on to ensure they go in to the draw for the next round.
Everton travelled to Macclesfield where Leon Osman's 42nd minute strike was enough to ensure the Premier League side's progress.
Craig Mackail-Smith was Peterborough's hero at the Hawthorns with his late equaliser ensuring West Brom will face an uncomfortable replay at London Road.
Jonas Olsson had put the Baggies in front but Mackail-Smith popped up to level the match.
A seven-goal thriller between Forest Green and Derby was decided by Steve Davies' 87th minute penalty for the Championship side.
It was hard luck on non-league Forest Green who surged in to an early two goal lead with strikes from Jonathan Smith and Alex Lawless.
Rob Hulse pulled one back for the visitors in the 40th minute and Martin Albrechsten levelled the tie on the stroke of half-time.
Paul Stonehouse got a third for Forest Green in the 72nd minute but Paul Green levelled the tie once more in the 76th before Davies slotted home his late penalty.
A brace for Andrew Johnson gave Fulham victory at Hillsborough against Sheffield Wednesday who had levelled the game with Tommy Spurr's 25 yard strike but Johnson broke Wednesday hearts with a winner two minutes from time.
Afonso Alves returned to scoring ways with his first goals since October putting Boro in to a 2-0 lead over non-league Barrow. Jason Walker pulled one back for the visitors in the 80th minute but Boro held on.
Herita Ilunga's first goal for West Ham sent the Hammers on their way against Barnsley and Mark Noble first won, and then converted a penalty shortly before the break. Carlton Cole added a third as the Hammers strolled into the fourth round.
In the other all Premier League tie of the day, Hull and Newcastle finished 0-0.
Last year's beaten finalists Cardiff progressed to the next round with a 2-0 win over Reading courtesy of goals from Ross McCormack and Joe Ledley.
Kettering won the all non-league tie against Eastwood to book their place in the fourth round.