Manchester United have moved out to 2/9 with Sky Bet to win the Premier League after suffering a 1-0 defeat against third-placed Arsenal.
Aaron Ramsey's second-half strike was enough to give the Gunners a deserved win which leaves reigning champions Chelsea within three points of top spot.
Carlo Ancelotti's men are now 10/3 to retain their league crown, whilst the Gunners are a 66/1 chance to win their first title since 2004.
Sky Bet Football Trader Mike Triffitt said: "It's looking like next week's game between Chelsea and Manchester United will be decisive.
"Anything other than a Chelsea win will surely see United crowned as champions, but a Blues win at Old Trafford would make them favourites to win their fourth Premier League crown."
Sky Bet have a number of title, relegation and top four markets for the Premier League.