United Kingdom - Manchester City's Premier League title challenge was rocked by a stunning 2-1 defeat at Newcastle, while Manchester United's late escape preserved Ole Gunner Solskjaer's unbeaten start in a dramatic 2-2 draw with Burnley on Tuesday.
City needed a win at St James' Park to close the gap on leaders Liverpool to one point ahead of the Reds' clash with Leicester on Wednesday.
But Pep Guardiola's 100th league game as City manager proved an evening to forget for the champions.
Second-placed City's loss means Liverpool, chasing their first English title since 1990, can move seven points clear with a win over Leicester.
It was a remarkable result given City took just 24 seconds to open the scoring.
Raheem Sterling crossed to David Silva and the City midfielder bravely headed it back as he collided with Newcastle goalkeeper Martin Dubravka.
Aguero pounced on the loose ball to poke home from close range for his 17th goal of the season.
But City lost their rhythm after that and were punished when Salomon Rondon equalised for Newcastle in the 66th minute from Isaac Hayden's header.
There was worse to come for City in the 80th minute.
Fernandinho's foul on Sean Longstaff gave Matt Ritchie the chance to score from the penalty spot and the Newcastle midfielder fired his effort low into the net.
It was City's first defeat since a loss at Leicester on December 26, ending a run of eight successive wins in all competitions.
Solskjaer had overseen eight straight victories in all competitions -- including six in the league -- since replacing the sacked Jose Mourinho in December.
He lost that perfect streak, but still finished impressed by United's never-say-die spirit at Old Trafford.
Ashley Barnes put Burnley ahead in the 51st minute and Chris Wood struck in the 81st minute to double their lead.
But former United star Solskjaer, serving as interim boss until the end of the season after temporarily leaving Norway's Molde, has had the midas touch.
And in the 87th minute Jeff Hendrick dragged back Jesse Lingard to concede a penalty that was converted by Paul Pogba.
United poured forward and Victor Lindelof snatched the equaliser in the last seconds.
Cardiff paid an emotional tribute to Emiliano Sala following the striker's disappearance, but Arsenal ran out 2-1 winners at the Emirates Stadium.
Sala signed from Nantes in a club-record deal, but the 28-year-old Argentine was one of two people on board the Piper Malibu plane which vanished in the Channel Islands last week en route to Cardiff.
Yellow daffodils were carried onto the pitch by Cardiff captain Sol Bamba and there was a minute's applause before kick-off for Sala.
A banner shown by Cardiff fans read: "We never saw you play, we never saw you score, but Emiliano, our beautiful Bluebird, we will love you forever more."
The Gunners took the lead in the 66th minute when Bruno Manga fouled Sead Kolasinac and Pierre-Emerick Aubameyang stroked home the resulting penalty.
Alexandre Lacazette's 83rd-minute strike ensured fifth-placed Arsenal moved level on points with fourth-placed Chelsea.
Nathaniel Mendez-Laing's stoppage-time goal was little consolation for Cardiff.
Ten-man Everton ruined Jan Siewert's first game in charge of Huddersfield with a 1-0 win over the bottom club at the John Smith's Stadium.
Former Borussia Dortmund reserve team boss Siewert replaced David Wagner, who left by mutual consent earlier in January.
But it was a nightmare start for Siewert as Richarlison's third-minute strike put Everton ahead.
Everton had defender Lucas Digne sent off for a professional foul on Adama Diakhaby in the 66th minute.
Wolves added to West Ham's woes with an emphatic 3-0 victory at Molineux.
Manuel Pellegrini's team suffered a shock FA Cup fourth round defeat at AFC Wimbledon on Saturday and they were brushed aside again by Wolves.
Romain Saiss gave Wolves the lead in the 66th minute before Raul Jimenez struck in the 80th and 86th minutes.
Second-bottom Fulham staged a superb fightback to boost their survival bid with a 4-2 win over Brighton.
Brighton raced into a two-goal inside 17 minutes thanks to Glenn Murray's double at Craven Cottage.
But Calum Chambers reduced the deficit two minutes into the second half and Aleksandar Mitrovic headed in for Fulham's 58th-minute equaliser.
Mitrovic capped the Cottagers' revival in the 74th minute before Luciano Vietto wrapped up the points five minutes later.