London - Chelsea's Premier League title ambitions took a major hit on Saturday when a John Terry own goal condemned the leaders to a shock 1-0 defeat at lowly Crystal Palace.
As Chelsea sank to their first defeat by Palace in 24 years, reigning champions Manchester United ended a week of turmoil with a 4-1 victory over Aston Villa thanks to two goals by England striker Wayne Rooney.
Terry headed a Joel Ward cross into his own goal early in the second half, amid suggestions it touched Palace defender Joe Ledley's hand on the way in.
Chelsea remained top of the table with 69 points, one ahead of Liverpool who can go top when they play Tottenham Hotspur on Sunday.
Manchester City, who were playing Arsenal later on Saturday, are three points off the lead with three matches in hand.
United came back from a goal down in a match that saw Juan Mata's first goal since arriving from Chelsea, a late Javier Hernandez goal and a protest by some United fans who flew a banner carrying the message 'Wrong One - Moyes Out' over Old Trafford as the match started.
The holders remained seventh, nine points off fourth-placed Arsenal.
Goals to England trio Jay Rodriguez (2), Rickie Lambert and Adam Lallana helped Southampton cruise to a 4-0 win over a toothless Newcastle United, while a Jonathan de Guzman double and a Wayne Routledge strike saw Swansea beat Norwich City 3-0 for only their third win in 18 matches
Peter Odemwingie's scoring streak since joining Stoke City continued as he registered the only goal of the match in a 1-0 win over Hull City, while Cardiff fought back from going two down to draw 3-3 at fellow strugglers West Bromwich Albion.