Liverpool - Manchester United head to Liverpool at the weekend for a significant test of Sir Alex Ferguson’s team’s improved away form.
United won a record 19th league title last season - moving ahead of Liverpool’s tally of 18 - despite their worst away record since the start of the Premier League.
They have improved that in the current campaign, with two wins and a draw from their three away games, with a 1-1 draw at Stoke the only points they have dropped so far.
But they will have to improve their record against their old rivals if they are to retain their unbeaten record.
They have lost three consecutive matches at Anfield, with Ferguson recently admitting that his team have been outfought on their recent trips to Merseyside.
Nemanja Vidic, who could return from a calf problem he sustained on the opening weekend of the season, was sent off in two of those three matches.
With Manchester City hosting Aston Villa, United know that they could lose ground in the title race without a positive result against Kenny Dalglish’s team.
England striker Wayne Rooney, who started his career at another of Liverpool’s bitter rivals Everton, feels the short trip to Anfield is the hardest game of the season.
"For me, Liverpool is always the toughest place to go to and win," Rooney said.
"They’ll be pushing to get into the top four and with the signings they’ve got they’re capable of doing that so we’ll have to be aware of them and try to beat them this time.
"They’ve made some good signings and obviously with them not qualifying for the Champions League last season they’ll be desperate to get back into that."
At least Ferguson’s injury concerns have eased in recent weeks, with Vidic coming through Serbia’s 1-0 defeat to Slovenia in midweek.
Tom Cleverley and Rafael Da Silva are now United’s only long-term absentees as they enter a congested phase of the season.
Dalglish’s return to the Liverpool manager’s job in January has added further spice to this fixture.
Ferguson made toppling fellow Scot Dalglish’s Liverpool his main priority when he moved to Old Trafford almost 25 years ago.
And the rivalry continued when United went head to head for the Premier League title with Dalglish’s Blackburn.
Dalglish, who may give Steven Gerrard a first Premier League start of the season, is keen to play down the importance of the two managers ahead of Saturday’s fixture and he is adamant that closing United’s seven-point advantage is his only motivation.
"We've got an opportunity to reduce the gap and it's up to us to take it," he said.
"They are a fantastic team, a hugely successful football club, and we know it's going to be a very difficult game. But I think they'll look at it and think exactly the same thing.
"I don't have any individual contest with Fergie. It's the football clubs who play. We don't play anymore. We can't really influence it other than in the build-up and preparation for the games. The most important thing for us is how we compete as a team on the pitch.
"I'm not egotistical, I'm not in this to get one over anyone else. This football club is more important than me and always will be.
"The result on Saturday is more important because it's about how millions of other people feel, rather than how I feel. It's not a boxing match, it's a game of football.
"They are in a position that everyone wants to be in, and that's top position in the league. You cannot argue with that because you want to be there yourself.
"They've set a standard for everyone else to follow or surpass and it's up to us to take up the challenge."
Glen Johnson, Martin Kelly, Daniel Agger and Fabio Aurelio have all overcome recent problems to be in contention for one of the most eagerly-awaited matches of the Premier League season.