London - With Premier League leaders Chelsea on top form, Manchester City will be hoping their Champions League win over Bayern Munich boosts confidence and re-ignites their title defence when they visit high-flying Southampton on Sunday.
Third-placed City have fallen eight points behind unbeaten leaders Chelsea after 12 games and face a tough test against a Saints side defying the critics who said they would struggle.
City's Sergio Aguero struck twice in the last five minutes to complete his hat-trick and secure a 3-2 victory at home to 10-man Bayern on Tuesday and Manuel Pellegrini's side have certainly been doing it the hard way in recent matches.
As well as staging the Bayern comeback, which revived their fading hopes of reaching the last 16, City fell behind early on in their last Premier League game at home to Swansea and needed goals from Stevan Jovetic and Yaya Toure to claim victory.
They also trailed 1-0 and 2-1 at Queen Park Rangers earlier this month before Aguero rescued a point seven minutes from time, three days after the debacle of a 2-1 home defeat by CSKA Moscow in which City finished with nine men.
Ronald Koeman's second-placed Southampton saw their run of four consecutive wins end with a 1-1 draw at Aston Villa on Monday but should be confident on home turf where they have won five and drawn one of six home league games -- scoring 17 and conceding just one.
Manchester United, after a troubled start to Louis van Gaal's reign, have quietly moved up to fourth, their improvement underlined by a 2-1 win at Arsenal on Sunday. United host Hull City on Saturday with Van Gaal remaining cautious.
"It is only one victory. We have to confirm that with victories in the next two home games. Then we can say, okay, we have the spirit now and we will go looking at upstairs and not downstairs," he said.
Fifth-placed Newcastle United, who have racked up five successive league wins in a remarkable turnaround after a dismal start, on Saturday visit West Ham United, one place below.
Leicester City, who have slipped into the relegation places after seven games without a win, will look to end their problems in front of goal at bottom side QPR.
Since putting five past Manchester United in September, the toothless Foxes have scored just twice.