Fresh off losing the English League Cup final to City before the international break, Arsenal saw another potential trophy slip from their grasp on Saturday when they conceded in the 85th minute to lose 2-1 at Southampton - a team in seventh place in the Championship.
Super sub Shea Charles struck with the match-winner for Southampton in the 85th minute as they bounced back from Viktor Gyokeres cancelling out Ross Stewart's first-half opener.
It was just a fifth defeat of the campaign for Arsenal, who sit nine points clear at the top of the Premier League but have plenty of soul searching to do after the costly back-to-back cup losses.
And it left City as hot favourites to clinch a cup double this season, with their thrashing of Liverpool securing a place in the FA Cup semi-finals for a record eighth straight season.
Mohamed Salah's failure from the penalty spot added to the woes of Liverpool, whose meltdown at Etihad Stadium will put more heat on under-pressure manager Arne Slot.
Chelsea also advanced, routing third-tier Port Vale 7-0. The semi-final line-up will be completed on Sunday when West Ham host Leeds, after which the last-four draw will be made.
Haaland's 18-minute hat trick started with a penalty in the 39th minute, heading home a cross from Antoine Semenyo in first-half stoppage time, and sweeping in a finish off the crossbar in the 57th.
Semenyo scored the other goal in the 50th for City. who sealed a return to Wembley Stadium two weeks after beating Arsenal there in the League Cup final.
"This club has to win trophies," said Haaland, who was described after the game as a "machine" by City assistant coach Pep Lijnders — the former Liverpool No. 2 who was deputising in the dugout while Pep Guardiola served a touchline suspension.
Salah, who announced during the international break he's leaving Liverpool after nine trophy-filled seasons, was beginning his long goodbye to the Reds but couldn't mark it with a goal. The best of the many chances he spurned came from a penalty, which City goalkeeper James Trafford palmed away in the 64th.
It was a record 18th straight home win for City in the FA Cup, dating to 2017. Guardiola's team shared a record with Clapham Rovers for reaching seven consecutive FA Cup finals but now hold it outright.
"The fighting spirit wasn't there enough, the mentality wasn't there enough," Liverpool midfielder Dominik Szoboszlai said. "None of us were there to be honest as much as we could.
"It's a hard time but we have to stick together."
Like City, Chelsea romped to a big win - though this one was expected on what proved a tough afternoon for Port Vale's Australian goalkeeper Joe Gauci.
Playing without Argentina midfielder Enzo Fernandez for disciplinary reasons, Chelsea still had more than enough to dispatch Port Vale at Stamford Bridge thanks to goals by Jorrel Hato, Joao Pedro, Tosin Adarabioyo, Andrey Santos, Estevao and Alejandro Garnacho. There was also an own-goal.
Chelsea have won the FA Cup eight times, most recently in 2018.
