The League Two side, who have been hit by financial problems throughout the season, went ahead thanks to Lee Hughes' 20th goal of the season.

Ben Davies' stunning free-kick doubled County's advantage before Jason Scotland pulled one back for Roberto Martinez's side.

County could not hold off a late Wigan onslaught though, and the Latics drew level through Watson's cool finish with seven minutes left.

Holders Chelsea booked their place in the last 16 of the competition with a comfortable 2-0 win at Preston.

The Blues saw off the threat of an upset despite a spirited effort from Darren Ferguson's side with the goals coming from Nicolas Anelka and Daniel Sturridge.

Reading caretaker-manager Brian McDermott added yet another Premier League scalp to his collection with a 1-0 win over Burnley.

Gylfi Sigurdsson scored the winner at the Madejski Stadium to put Reading, who beat Liverpool in the third round, into the last 16.

Wolves' Ronald Zubar struck late on to ruin Crystal Palace's chances of a shock at Molineux.

Darren Ambrose played Alan Lee in for Palace's opener before Mick McCarthy's side drew level with a long-range strike from David Jones eight minutes before the break.

Ambrose's excellent free-kick put Palace back in front but Zubar's 25-yard effort earned a replay for McCarthy's side.

Fulham had to come from behind to beat 10-man Accrington Stanley at the Crown Ground.

Accrington, who sit 70 places behind Fulham in the league standings, went behind to an Erik Nevland goal before Michael Symes turned home an equaliser.

The home side's chances of a shock took a blow just before half-time when Darran Kempson was sent off and Fulham took advantage of their numerical superiority by taking the lead through a well-worked Damien Duff goal.

Bjorn Helge Riise then crossed for Gera to seal the Cottagers' 3-1 win.

Portsmouth ended a miserable week on a high with a 2-1 win over Sunderland at Fratton Park.

The home side, beleaguered by off the field financial problems, went behind to a Darren Bent strike before John Utaka's double put Avram Grant's through.

Aston Villa survived a scare to beat League One side Brighton at Villa Park.

Tommy Elphick's goal gave Brighton the lead before goals from Nathan Delfouneso, Ashley Young and Fabian Delph handed Martin O'Neill's side a 3-1 lead.

Nicky Forster pulled one back for Brighton but Villa held on for the win.

League One side Southampton overcame Championship side Ipswich at St Mary's.

Strikes from Wayne Thomas and Michael Antonio gave the Saints the lead before Pablo Counago pulled one back for Roy Keane's men.

West Brom booked their place in the fifth round with a 4-2 win over Championship promotion rivals Newcastle.

West Brom went in 2-0 up with a Jonas Olsson strike and a Graham Dorrans penalty before Andy Carroll's second-half volley gave the travelling Toon Army hope.

Ryan Taylor was sent off after pulling down Jerome Thomas in the box before Dorrans' converted the penalty

Thomas made it 4-1 before Carroll pulled one back for Chris Hughton's side but it was the Baggies who went through.

Gretar Steinsson and Johan Elmander scored second-half goals to see off Sheffield United and give Owen Coyle his first win as Bolton manager,

Two late goals gave Cardiff a 4-2 win over Championship rivals Leicester.

Jay Bothroyd broke the deadlock for Cardiff before Michael Morrison and Dany N'Guessan put Leicester 2-1 ahead.

Peter Whittingham's free-kick put Cardiff level before Chris Burke and Ross McCormack sealed the win for Cardiff.

Birmingham sealed a 2-1 win over Everton in the all-Premier League tie at Goodison Park.

Goals from Christian Benitez and Barry Ferguson put Birmingham 2-0 up before Leon Osman gave the home fans some hope with a well taken header in the second half.

In the day's other game James McEveley snatched a last-gasp winner for Derby against Doncaster.

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In the late kick-off, Leeds striker Jermaine Beckford was the hero again when he slotted home a last-gasp penalty at White Hart Lane to earn a 2-2 draw against Tottenham.

Casper Ankergren will also take the plaudits after saving Jermain Defoe's first-half penalty but it was Beckford who grabbed two equalisers to add to his winner in the previous round against Manchester United.

Peter Crouch netted the opener but Beckford replied after the break. The Leeds striker then won and scored a stoppage-time spot-kick after substitute Roman Pavlyuchenko looked to have earned Spurs a win.