Jamie Vardy ended a seven-game scoring drought as Leicester City usurped Arsenal at the top of the Premier League table with a 3-0 victory over Stoke City on Saturday.
A day that began with an astonishing game at Carrow Road that finished Norwich City 4-5 Liverpool ended with Leicester three points clear of Arsenal, who host Chelsea on Sunday, and Manchester City.
Sergio Aguero scored twice as Manchester City drew 2-2 at West Ham United, taking them above Arsenal on goal difference, but Manchester United's season took another downward lurch in a 1-0 home defeat by Southampton.
"I don't know if we are a (title) contender at this moment," said Leicester manager Claudio Ranieri.
"February is a big month and after that month I can say something more realistic."
Vardy rounded Jack Butland to score his 16th goal of the campaign as Leicester sank Stoke at the King Power Stadium, with Danny Drinkwater and Leonardo Ulloa also on target.
Manchester City were unable to follow suit as they dropped points at West Ham, giving Arsenal a chance to move three points above them.
West Ham took the lead inside a minute at Upton Park as Enner Valencia drilled home after Cheikhou Kouyate's cross was deflected into his path.
Aguero hit the post with an audacious lob from wide on the left before equalising with a ninth-minute penalty after he had been tripped by Carl Jenkinson.
West Ham regained the lead in the 56th minute as Nicolas Otamendi allowed a long throw to bounce over him and Valencia prodded home, but Aguero coolly converted a second equaliser with nine minutes left.
"It was not what we wanted before the game," City manager Manuel Pellegrini told Sky Sports.
"It was a difficult game. I was not happy with the way we conceded the second goal."
Aguero's second goal prevented West Ham from knocking Manchester United out of the top five, but there was little for under-fire United manager Louis van Gaal to cheer after his side were booed off at Old Trafford.
Van Gaal sympathised with United's fans, saying: "They are right, I cannot deny that. I have seen the match also. In better or for worse, we have to stick together."
- Alli stunner -
Charlie Austin gave Southampton victory in the 87th minute, meeting James Ward-Prowse's right-wing free-kick with an unerring header in his first appearance since signing from Queens Park Rangers.
A beaming Austin said: "It does not get any better than that."
In a further blow to Van Gaal, right-back Matteo Darmian was forced off after a second-half collision with Shane Long, exacerbating United's defensive injury crisis.
United are now 10 points below Leicester, five points off the Champions League places and only three points above Liverpool, who saw off Norwich in a dizzying game thanks to a 95th-minute winner from Adam Lallana.
After Roberto Firmino had put Liverpool ahead from James Milner's pass in the 18th minute, Norwich hit back with a clever Dieumerci Mbokani back-heel, a goal by debutant Steven Naismith and a Wes Hoolahan penalty.
But goals from captain Jordan Henderson and Firmino drew Liverpool level and although Milner's 75th-minute effort was cancelled out by Sebastien Bassong's drive in the 91st minute, Lallana had the final word.
"At the end we can be really happy with nearly everything, especially with the three points," said Liverpool manager Jurgen Klopp, who lost his glasses in the touchline celebrations after Lallana's winner.
"I usually have a second pair of glasses, but I can't find them because it's hard to find glasses without glasses!" he joked.
Tottenham Hotspur tightened their grip on fourth place by coming from behind to beat London rivals Crystal Palace 3-1 thanks to a magnificent Dele Alli goal.
Palace took a 30th-minute lead when Jan Vertonghen turned Wilfried Zaha's cross into his own net, but Harry Kane equalised in the 63rd minute by heading in Nacer Chadli's cross.
Alli struck in the 84th minute, flicking the ball over a defender's head and brilliantly volleying home from outside the box, before Chadli added a third goal from long range in stoppage time.
Newcastle United remain in the bottom three after losing 2-1 at Watford, who prevailed through goals from Odion Ighalo and Craig Cathcart, with Jamaal Lascelles reducing the arrears.
Sunderland are also still in the relegation places after drawing 1-1 at home to Bournemouth, with Patrick van Aanholt cancelling out Benik Afobe's headed opener for the visitors.
Elsewhere, bottom club Aston Villa drew 0-0 at West Bromwich Albion.