Chelsea close on United
London - Didier Drogba scored for Chelsea as they won their fourth straight match under temporary manager Guus Hiddink with a 1-0 victory away to Premier League strugglers Portsmouth on Tuesday.
Drogba's goal 11 minutes from time at a wet and windy Fratton Park saw Chelsea close the gap on leaders Manchester United to four points.
But the reigning champions, who are in action away to Newcastle on Wednesday, have two games in hand.
Liverpool joined Chelsea on 58 points after they bounced back from the shock of their 2-0 loss to Middlesbrough with a 2-0 victory at home to Sunderland.
And in Tuesday's other Premier League match, Nicklas Bendtner scored twice as Arsenal ended a run of four consecutive goalless league draws with a 3-1 win away to bottom-of-the-table West Bromwich Albion.
That victory saw the Gunners move to within three points of fourth-placed Aston Villa in the race for a Champions League place.
"I had prepared my third subsutitution but at a good moment the goal came," Hiddink told Sky Sports.
But the Dutchman was cautious regarding talk of Chelsea challenging United. "If they can give us this one game also but it (this result) is good.
"The team is mentally strong. They showed in difficult circumstances a lot of character. It's good to keep the pressure on."
A counter-attack led by Peter Crouch in the second-half led to a fine chance for Niko Kranjcar but the Croatia international shot wide.
And that miss became all the more painful for Pompey when Drogba fired Chelsea into the lead in the 79th minute following a cross from Jose Bosingwa.
Despite their defeat, Pompey's first under boss Paul Hart, who was later confirmed as manager until the end of the season, the south coast club remained above the relegation zone.
After a goalless first-half at Anfield, Liverpool eventually took the lead when Steven Gerrard's header across goal was turned in by David Ngog in the 52nd minute.
And it was 2-0 to the Reds when Israel international Yossi Benayoun pounced on a mistake by keeper Martin Fulop, who fumbled Ngog's cross, to score from close range.
"He showed he is quality," said Liverpool manager Rafael Benitez of Ngog.
"He is a young player who has just arrived, and I think he has a great future here."
Arsene Wenger, the Arsenal manager, insisted his faith in the team had never wavered.
"We kept going and there is a very strong, healthy spirit in this team.
Arsenal had to wait only as long as the fourth minute at The Hawthorns to end their goal drought when Bendtner put them ahead.
A corner was cleared to Denilson and the Brazilian played the ball out to the unmarked Bendtner and the forward's scuffed shot beats Baggies goalkeeper Scott Carson.
However, three minutes later the home side were level when Chris Brunt's 25-yard free-kick went through a gap in the Arsenal wall and left Gunners keeper Manuel Almunia helpless.
But seven minutes before half-time Arsenal restored their lead.
Andrei Arshavin's inswinging free-kick in from the left was met by the unattended Kolo Toure and the central defender's first goal in a year made it 2-1 to the Gunners.
And there was still time before the break for Denmark striker Bendtner to make it 3-1 when Toure's long ball over the top evaded the West Brom defence and Bendtner controlled it on his knee before volleying home.
In the second-half, Bendtner then beat a couple of players only to miss out on a hat-trick when his shot hit the post.