The 25-year-old, who ran at United’s defence like a bulldozer all day, completed his double in the 68th when the visitors lost the ball. Haaland, lining up at the centre circle, easily outsprinted Harry Maguire to Bernardo Silva’s ball forward for another one-on-one with Bayindir.
“You could feel it from the fans, we needed this,” Haaland said. “You always want to win the derby but you could feel it extra today. I’m so relieved, so happy we managed to do it all together. We have to keep going. Today we’re super happy.”
The match lacked the intrigue of derbies past with both teams going into the game mid-table after sputtering starts.
City climbed to eighth with their second win from four, while United are 14th with just one victory.
Haaland almost had a hat-trick, thanks to United’s shambles at the back. He had Bayindir beaten but missed a sitter to hit the post. Guardiola was already celebrating, but then held his head in disbelief.
The victory capped quite a week for Haaland, who had five goals on Tuesday when Norway pummelled Moldova 11-1 to maintain their perfect record in men’s World Cup qualifying.
He also scored his 50th goal in his 50th home Premier League game for City. In the competition’s history, only Alan Shearer required fewer home appearances, 47, to hit 50 goals.