Brighton and Hove Albion have suffered shock defeats as they tumbled out to Championship opposition in the third round of the FA Cup.
Harry Arter scored a stunning winner as Villa were beaten 2-1 at Fulham on Saturday while Brighton were upended 1-0 at home by Sheffield Wednesday.
Newcastle need a replay after they were held 1-1 at League One side Rochdale while League One Tranmere Rovers produced a brilliant fightback as they came from 3-0 down to draw 3-3 at Premier League Watford.
Arter had not scored since November 2017 but his left-foot strike 16 minutes from time found the top corner and gave Fulham victory over Villa.
Brighton fell at the first hurdle as Adam Reach won it for Sheffield Wednesday with the only goal on 65 minutes.
Manchester City made a solid start to their defence as they beat League Two side Port Vale 4-1 to cruise into the fourth round.
Goals from Oleksandr Zinchenko, Sergio Aguero, Taylor Harwood-Bellis and Phil Foden ultimately made it a routine day for City, although Tom Pope had equalised for a Vale side sitting 74 places lower in the English standings.
Manchester United will have to replay after a goalless draw at Wolves. United, like City, made multiple changes to their starting line-up in a tie that finally came alive in the second half after a lacklustre opening 45 minutes.
Marcus Rashford came off the bench to strike the bar for United and Matt Doherty had a goal ruled out for Wolves.
Forty-year-old Aaron Wilbraham was the hero for League One Rochdale as they secured a replay at St James' Park thanks to a 1-1 draw with Newcastle.
Miguel Almiron's early goal looked to have won it for Newcastle but Wilbraham popped up in the box to hammer in the equaliser from close range with 11 minutes to go.
"We played football in the second half," Abraham said.
"We mixed it up well and were unlucky not to win the game.
"It will be a great experience for the lads to go up to St James' Park. We will go there to try and express ourselves."
Newcastle manager Steve Bruce said his side let Rochdale off the hook.
"We should have been out of sight and therein lies our big problem - we don't score often enough," he said.
Teenage striker Adam Idah scored his first senior hat-trick - in just his second appearance for the Premier League's bottom side Norwich - as his side won 4-1 at Preston North End.
Goals from Tom Dele-Bashiru, Nathaniel Chalobah and Roberto Pereyra seemed to have put Watford through as they led Tranmere 3-0 with around 30 minutes to go.
But Connor Jennings, Manny Monthe and Paul Mullin, with a penalty, grabbed the goals as they secured a replay.
Will Smallbone and Jake Vokins gave Southampton a 2-0 win over Huddersfield Town while Jay Rodriguez scored twice as Burnley saw off Peterborough 4-2.
Tom Eaves scored a hat-trick, with the winner three minutes into injury time, as Hull won 3-2 at 10-man Rotherham, earning praise from his manager Grant McCann.
"He's a big lump who can finish," he said.
"He anticipated the last one and I liked that the best. It was a great header."
Millwall, Birmingham, Oxford and Brentford all advanced but Bristol City and Shrewsbury, Cardiff and Carlisle and Reading and Blackpool will all have to replay.
Premier League leaders Liverpool meet neighbours Everton on Sunday, when Chelsea, Tottenham and West Ham also enter the fray.