Matt Ritchie condemned Manchester United to a shock 1-0 defeat at struggling Newcastle, while Liverpool cemented their top four place with a 2-0 win over Southampton on Sunday.

United's second defeat in their last three Premier League games leaves them 16 points behind leaders Manchester City.

Jose Mourinho's second placed side, beaten by Tottenham in their last away game, were rarely at their best at St James' Park and paid the price in the 65th minute.

United defender Chris Smalling was booked for needlessly diving inside his own half and from the resulting Jonjo Shelvey free-kick, Dwight Gayle latched onto a header and played a backheel towards Ritchie.

His run was completely untracked by United's sloppy defence and the Newcastle winger fired low past David De Gea.

Mourinho responded by pulling off Paul Pogba after another underwhelming display. And United should have equalised soon after, but when Newcastle failed to clear a corner, Anthony Martial saw two shots blocked on the line by Gayle.

"Newcastle fought like animals, I hope they take that as a compliment. The gods of football were on their side," Mourinho said. "It wasn't going to happen for us today. Newcastle gave what they have, that's a beautiful thing in football.

"We made a defensive mistake and when they are in front they had only one thing in mind and gave their lives to keep a clean sheet."

At St Mary's, Liverpool moved above Tottenham into third place as goals from Roberto Firmino and Mohamed Salah killed off lowly Southampton.

Jurgen Klopp's side took a sixth minute lead when Brazil forward Firmino netted for the 20th time this season and doubled it Liverpool in the 42nd minute when Firmino turned provider for Salah with a fine flicked pass that the Egypt forward slotted home for his 29th club goal of a dream first season with the Reds.

Klopp's men are four points clear of fifth placed Chelsea, who face West Bromwich Albion on Monday, as the battle hots up to qualify for the Champions League.