It was a day of upsets in the third round of the FA Cup as fourth-tier Newport County beat Premier League high-flyers Leicester City 2-1, while Oldham defeated top-flight strugglers Fulham by the same scoreline.
Premier League champions Manchester City thrashed Rotherham 7-0, with Watford beating non-league Woking 2-0.
But Barnet ensured there would be a non-league presence in the fourth round with a 1-0 win away to second-tier Championship club Sheffield United.
It had seemed visitors Leicester, seventh in the Premier League and top-flight champions in 2016, would leave Rodney Parade with a draw when Rachid Ghezzal’s shot eight minutes from time cancelled out Jamille Matt’s 10th-minute header.
But, with five minutes left, Newport were awarded a penalty after Leicester’s Marc Albrighton inexplicably raised his arm to block a cross into the box and Padraig Amond made no mistake from the spot to spark delirious scenes among the Welsh club’s supporters.
Denis Odoi put Fulham ahead in the 52nd minute at Craven Cottage but Sam Sturridge drew Oldham level with a penalty before Callum Lang’s header two minutes from time sealed a comeback win.
Daniel Iversen compounded Fulham’s misery by saving an Aleksandar Mitrovic penalty – his first touch after coming off the bench – just moments earlier.
Manchester City boss Pep Guardiola made eight changes from the team that beat Premier League leaders Liverpool on Thursday but still fielded a strong side for the visit of Championship club Rotherham.
Raheem Sterling out City ahead in the 12th minute and they scored two more goals late in the first half through Phil Foden and a Semi Ajayi own-goal.
Gabriel Jesus made it 4-0 early in the second period before Riyad Mahrez, Nicolas Otamendi and Leroy Sane added further goals.
Elsewhere, Barnet beat Championship high-flyers Sheffield United thanks to Shaquile Coulthirst’s 21st-minute penalty.
Premier League leaders Liverpool will complete a third round that started with Tottenham’s 7-0 thrashing of Tranmere on Friday when they face top-flight rivals Wolves on Monday.