Liverpool got back to winning ways after back-to-back Premier League defeats by beating Portsmouth 4-1 at Anfield on Saturday, ending the south coast club's run of six away victories in the competition.
Yossi Benayoun and an own goal put Liverpool 2-0 up after 16 minutes. Benjani Mwaruwari pulled one back for Portsmouth before a double by Spaniard Fernando Torres underscored the home team's dominance.
Arsenal survived a scare from Tottenham Hotspur, who missed a penalty at 1-1, before emerging 2-1 winners in a London derby on Saturday to extend their Premier League lead to four points.
Arsenal were below their best for much of the game at the Emirates Stadium but took the points with two pieces of clinical finishing.
Emmanuel Adebayor opened the scoring in the 48th minute after he was sweetly set-up by a Cesc Fabregas backheel.
Spurs equalised through Dimitar Berbatov in the 66th minute but blew their chance of a first win over their local rivals since 1999 when Arsenal keeper Manuel Almunia saved Robbie's Keane's penalty six minutes later after Berbatov had been tripped.
Arsenal took full advantage when teenaged Danish striker Niklas Bendtner climbed off the bench to head home a Fabregas corner in the 76th minute.
Manchester City, who drew 1-1 at Aston Villa, remain fourth on 34 with Liverpool fifth on 33.
West Ham United and Reading claimed late goals to secure 2-1 wins over Middlesbrough and Sunderland respectively while Bolton Wanderers beat Birmingham City 3-0.