Boos greet United's fourth match without a win as Saints hold on at Old Trafford
Manchester United failed to win for a fourth successive game as they were held to a goalless draw by Southampton at Old Trafford.
On a frustrating evening for Jose Mourinho's side, they lost Romelu Lukaku early after he took a blow to the head and then saw a late goal ruled out when Paul Pogba touched in Nemanja Matic's shot from an offside position.
It was far from all one-way traffic, with David De Gea producing two fine saves.
There were boos at full-time from the United fans, who have seen their side beaten in the Carabao Cup by Bristol City and then held to draws by Leicester, Burnley and now Southampton.
United drop below Chelsea to third in the Premier League table after Antonio Conte's men became the latest to profit from Stoke's leaky defence.
The Potters have conceded more goals than any other team in the league and, with Mark Hughes naming a weakened side, Chelsea took full advantage in a 5-0 victory.
Antonio Rudiger struck very early and they were two up with less than 10 minutes on the clock thanks to Danny Drinkwater's brilliant volley.
When Pedro made it 3-0 in the 23rd minute, it seemed any score was possible, but Chelsea did not find the net again until 17 minutes from time, when Willian picked himself up to score from the penalty spot after he had been felled by Geoff Cameron.
Davide Zappacosta rounded off the scoring in the 88th minute.
Two goals in the final five minutes gave Carlos Carvalhal a dramatic 2-1 debut victory as Swansea boss.
The Swans looked to be slipping to defeat against Watford at Vicarage Road, with Andre Carrillo's 11th-minute strike separating the sides.
But Jordan Ayew levelled in the 86th minute and substitute Luciano Narsingh scored an unlikely winner with the match heading into injury time.
The result lifted Swansea off the bottom of the table and provided former Sheffield Wednesday boss Carvalhal with a dream start to his tenure in Sou th Wales.
Liverpool secured a valuable three points in the race for the top four by coming from behind to beat Leicester 2-1.
Jamie Vardy opened the scoring after only three minutes and the Foxes held on until the 52nd minute, when Mohamed Salah netted his 16th league goal of the season. Number 17 followed 24 minutes later and proved to be the winner.
Bournemouth climbed out of the relegation zone after Ryan Fraser's deflected effort in the 89th minute earned them a 2-1 win over Everton.
Fraser opened the scoring 33 minutes in before Idrissa Gueye equalised 12 minutes after the restart.
There was another clean sheet for Burnley in a goalless draw with Huddersfield, while Newcastle's clash with Brighton also ended goalless.