After knocking Newcastle out in the third round, Brighton and Hove Albion were hoping to claim another Premier League scalp. But the Seagulls won't see the fifth round, after losing 3-2 to Arsenal.
Middlesbrough and Aldershot met for the first time - but it wasn't a happy first meeting for the Hampshire side, losing 2-1.
Reading were at home to Sheffield United - the match there ended victorious for the Royals, 4-0.
Bournemouth and Portsmouth were both at home. The Cherries continue their fine form beating Crewe 3-1. In a battle of the bottom two, Pompey suffered a devasting blow to their survival hopes, losing 3-1.
Swindon's trip to Tranmere has been postponed due to a frozen pitch.
Oxford United return from Fleetwood heavy hearted, having lost 3-0.
Gillingham drew one all with York on home turf - a win WOULD have put them at the top of the table.