Liverpool manager Rafael Benitez and Chelsea counterpart Guus Hiddink have pledged to keep pushing Manchester United for the Premier League title.
Both teams won on Tuesday and now lie four points behind United, who have two games in hand and face Newcastle on Wednesday.
Liverpool, who defeated Sunderland 2-0, visit United on 14 March and Benitez said: “If we win that, things may well be a lot different.”
“United are in a good position,” added Benitez. “United have experience but clearly it’s important for us to win.
“Chelsea won too so United have to win if they want to keep the difference.”
The win over Sunderland, which followed Saturday’s defeat by Middlesbrough, was a confidence booster for Benitez’s side.
“This win has lifted everyone’s spirits after the bad defeat at the weekend,” added Benitez.
“We needed a win. The team needed to show character and that is what they produced.”
Hiddink has enjoyed three league wins and a Champions League victory over Juventus since taking over as Blues boss and has sensed a strong desire in his players.
After last night’s 1-0 win at Portsmouth, Hiddink said: “It is good for everyone in this championship to keep the pressure on the number one team.”
“United have games in hand and they have a buffer,” he said.
“They are an experienced team but that is why it is good that we keep on winning. It keeps the pressure on.
“What is good in this team is that they react when there are difficulties.
“Many players react in a way I normally don’t like but this team is not happy when things are not going well and they make an extra effort to get their rewards.
“I notice there is a desire to have success and we have some key players who are demanding a lot from themselves and also from the other ones, which is key for big players with a big status.
“They challenge each other and it is very open. It shows the team is not fed up and has desire.
“In difficult circumstances we are satisfied with a win. It was a tough win over Portsmouth.”
United boss Sir Alex Ferguson is refusing to get carried away with his team’s lead at the top of the table, citing the recent downturn in form for longtime Spanish league leaders Barcelona.
“Barcelona have been playing Saturday-Wednesday-Saturday since January,” commented Ferguson before Tuesday’s Premier League matches.
“They did have an 11-point lead, now it is four and for the first time this season they lost a game after being in front.
“It is a warning, and there are plenty of them, that if you take your foot off the pedal you can get a kick in the teeth.”