West Bromwich Albion dealt Manchester United's hopes of automatic Champions League qualification a serious blow with a smash-and-grab 1-0 victory at Old Trafford on Saturday.
West Brom took a 64th-minute lead when Chris Brunt's free-kick cannoned into the net off team-mate Jonas Olsson and goalkeeper Boaz Myhill preserved their advantage by saving a Robin van Persie penalty. It meant that United fell to a third consecutive Premier League defeat for the first time since December 2001, following previous losses at Chelsea and Everton.
Victory would have provisionally taken Louis van Gaal's side into second place, but they were left two points below both Manchester City and Arsenal, having played a game more than the former and two more than the latter. With only three games left to play, it leaves United struggling to avoid finishing in fourth place, which would oblige them to enter next season's Champions League in the play-off round.
Bottom club Burnley, promoted last season, lost 1-0 at West Ham United, who prevailed through a 24th-minute Mark Noble penalty after visiting defender Michael Duff had been sent off for a foul on Cheikhou Kouyate.
QPR are only a point better off following a 2-1 defeat at Liverpool that took place against a sombre backdrop following the death of Rebecca Ellison, the wife of QPR defender Rio Ferdinand, from breast cancer. With players from both teams sporting black armbands, Liverpool took a 19th-minute lead through Philippe Coutinho. Leroy Fer equalised with a volley from a Joey Barton corner in the 73rd minute, before Liverpool captain Steven Gerrard saw a penalty saved by former England colleague Rob Green. But the momentum swung back in the hosts' favour when Nedum Onuoha was sent off for a second bookable offence and Gerrard atoned for his penalty blunder by heading home an 87th-minute winner.
Sunderland moved in the opposite direction after Jordi Gomez scored two penalties in a 2-1 win at home to Southampton, who replied through Sadio Mane and had James Ward-Prowse sent off. The victory left Dick Advocaat's side a point below fourth-bottom Leicester City with a game in hand.
Aston Villa likewise bolstered their chances of avoiding the drop as Christian Benteke took his tally to 11 goals in nine games with a brace in a 3-2 win over Everton. Tom Cleverley also scored for Villa, with Romelu Lukaku and Phil Jagielka hitting back for Everton, as Tim Sherwood's side preserved their two-point cushion over the bottom three.
Leicester enhanced their survival hopes with a one-sided 3-0 home win over flatlining Newcastle United, with Leonardo Ulloa scoring twice and captain Wes Morgan also finding the net. Newcastle finished the game with nine men after defenders Mike Williamson and Daryl Janmaat were both sent off for two bookable offences. Williamson's second booking was for a wild touchline lunge on Jamie Vardy and manager John Carver accused the centre-back of being sent off deliberately.
Elsewhere, Jefferson Montero and Ki Sung-yeung scored late goals as Swansea City won 2-0 at home to Stoke City, who had Marc Wilson sent off.