Newcastle United completed a spirited comeback to create a massive twist in this season's title race - with Liverpool having the chance to go SEVEN points clear of Manchester City on Wednesday night.
Goals from Salomon Rondon and a Matt Ritchie penalty cancelled out Sergio Aguero's opener just 23 seconds in.
City had the chance to go within a point of league leaders Liverpool; but now face the possibility of going seven behind them, if the Reds can beat Leicester City at Anfield on Wednesday evening.
Image via Premier League
It took the champions just 23 seconds to dent Newcastle's hopes. Aguero was on hand to tap in after David Silva's flick on.
A real nightmare start for Rafa Benitez and his men, whose game plan was immediately broken.
Aguero scoring his 15th Premier League goal against Newcastle in 13 appearances (image via Premier League)
City again had the ball in the net. And it was again Aguero. But this time referee Paul Tierney disallowed the quick free-kick from Kevin De Bruyne, as he wasn't ready for it!
David Silva came close to doubling the champions' advantage, but his header was cleared off the line by Fabian Schar.
City went in a goal to the good at the break, and it looked an uphill task from Newcastle's perspective.
But a spirited performance in the second-half from the Magpies caused the champions all sorts of problems.
Newcastle's top scorer, Rondon, steered the ball past Ederson and into the net, after the ball had been looped back in the box.
14 minutes later, and St. James' Park was bouncing. Sean Longstaff was brought down by Fernandinho and the Magpies had a spot kick.
Ritchie stood up to take it, with the whole of Liverpool with him, and smashed it past Ederson to give them a precious lead.
Newcastle held on. Benitez held on. The battle of the Spaniards brought an unlikely winner on Tyneside.
The Managers
Newcastle United boss Rafael Benitez: "It was a great effort from everyone and to win against a team as good as Manchester City. They have everything.
"They are so good so when you get three points against them you know the players have done really well.
"We had a couple of situations where they were dangerous on the counter-attack but on the whole, we defended well. We scored two goals and kept pushing until the end so you have to be very proud of the players."
Manchester City manager Pep Guardiola: "It is difficult (to take). We have a chance to do it (catch leaders Liverpool) but we need to win our games.
"The advantage is not there but we need to continue. We have to do our games and know what we have to do. You can lose. Football is competitive."