England midfielder Frank Lampard struck four goals on Wednesday as Chelsea rebounded from their FA Cup reverse at Barnsley at the weekend to defeat Derby 6-1 in the Premier League.
Lampard's fellow England international Joe Cole and Ivory Coast's Salomon Kalou scored the other goals while David Jones notched a late consolation for struggling Derby.
Chelsea moved to within five points of league leaders Arsenal, who top the standings with 66 points from 29 games two ahead of defending champions Manchester United, who have a game in hand.
Aston Villa, chasing fourth place and a Champions League spot, were held 1-1 by Middlesbrough at Villa Park.
Stewart Downing scored midway through the first half for Middlesbrough with Gareth Barry equalising for the home side after the interval.
Portsmouth striker Jermaine Defoe continued his recent run of prolific form with two early goals for the FA Cup semi-finalists at home to Birmingham.
Fabrice Muamba and Sebastian Larsson scored for Birmingham to bring the sides level before Hermann Hreidarsson and Nwankwo Kanu sealed a 4-2 win.
