LONDON - Manchester City are romping away in the title race but the Premier League continued to throw up surprises on Sunday as first Manchester United and then Everton dropped points to sides written off as relegation fodder.
United had the opportunity to cut City's lead to five points but were held to a disappointing 1-1 draw at second-bottom West Bromwich Albion.
Everton then wasted an opportunity to move level on points with fourth-placed city rivals Liverpool having played two fewer games but suffered a 2-0 defeat at home to lowly Fulham.
However, Arsenal returned to the top half of the table in 10th place as Pierre-Emerick Aubameyang marked his first start after an absnece for personal family issues to score a hat-trick in a 4-2 home victory over Leeds United.
Southampton's slump worsened as they lost a sixth league game in succession, going down 2-1 at home to Wolverhampton Wanderers for whom Pedro Neto bagged a superb winner.
Manchester City's 11th straight league win, at home to Tottenham Hotspur on Saturday, put them on 53 points from 23 games with United and Leicester City, who beat Liverpool 3-1 on Saturday, both on 46 from 24.
Liverpool trail on 40 points and could drop to sixth if Chelsea at least draw and West Ham United win on Monday.
West Brom took the lead early on at the Hawthorns through on-loan Senegalese striker Mbaye Diagne's header. United's response was lacklustre until inspirational Portuguese midfielder Bruno Fernandes volleyed home in the 44th minute.
United then dominated the second half with defender Harry Maguire having a 95th-minute header tipped onto the post.
Despite the setback, United manager Ole Gunnar Solskjaer said his side could still chase down City.
"We won't let them (City) run away with it -- we're playing them soon (in March). We're not giving it away early -- no we're not," he said.
The door looked wide open for Everton to make a big statement about their top-four credentials, but Carlo Ancelotti's side produced a dismal display against Fulham who claimed a first league win since November.
Fulham's Nigerian striker Josh Maja scored his first two goals for the club to rekindle their hopes of avoiding relegation, although they are still in deep trouble.
Scott Parker's third-bottom side are seven points behind 17th-placed Newcastle United and the safety zone, with West Brom a further five behind and Sheffield United 14 adrift.
"I know what we need to do and the players do too. We can't control what is around us, we just need to win football matches. If we do that I know it will be OK," Parker said.
Everton boss Carlo Ancelotti said Wednesday's 5-4 FA Cup fifth round win against Tottenham in extra time had taken its toll but praised Fulham for a deserved victory.
"Physically we didn't have the necessary power to match the intensity of Fulham," the Italian said. "I'm surprised they're in the bottom three. They deserved to win tonight."
Everton remained in seventh place with 37 points although they have games in hand of most of the teams around them.
Aubameyang had not started in any of Arsenal's last five games but the club skipper returned with a bang to grab his first Premier League hat-trick, netting twice before the interval and again just after thre break.
"It's been a tough time for me but now it's time to get the smile back, win games and score goals," the Gabon forward, whose mother has been ill, said of his goalscoring return.
West Ham United face Sheffield United on Monday before Chelsea host Newcastle United.
(Reporting by Martyn Herman; Editing by Ken Ferris)