London: Fourth-tier Newport County beat Premier League high-flyers Leicester City 2-1 to record a memorable upset win in the third round of the English FA Cup on Sunday, with Oldham defeating 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.
"It's the first time I've beaten a Premier League club as a manager so it's one I'll never forget," Newport boss Michael Flynn told the BBC.
"It's unbelievable," he added after Newport's first FA Cup win against a top-tier club since they beat Sheffield Wednesday in the third round back in the 1963/64 season.
Leicester manager Claude Puel praised Newport by saying: "They believed in themselves and created the upset."
The Frenchman added: "I think we had an experienced team to manage this game. We had eight players who won the title."
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.
"It is Roy of the Rovers stuff," said Oldham caretaker boss Pete Wild.
"The character in the dressing room is phenomenal."
Fulham manager Claudio Ranieri, explained his decision to have Mitrovic take the spot-kick by saying: "I said to him to shoot the penalty because he's our man to shoot the penalty."
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.
Foden's goal was the England Under-21 international's first in senior football at the Etihad.
Elsewhere, Barnet beat Championship high-flyers Sheffield United thanks to Shaquile Coulthirst's 21st-minute penalty.
"It's unbelievable," said Barnet captain Callum Reynolds after the north London club's triumph.
Watford manager Javi Gracia changed his entire starting side from the team that drew 3-3 at Bournemouth.
But hopes of Woking, 110 places adrift of the Hornets, enjoying a shock win were dented by Will Hughes's 13th-minute curled shot from the edge of the area.
Watford doubled their lead 16 minutes from time through Troy Deeney.
Millwall came from a goal down to beat Championship rivals Hull 2-1, substitute Shane Ferguson scoring twice inside the closing eight minutes, with QPR also winning 2-1 against second-tier leaders Leeds.
On Saturday, holders Chelsea cruised to a 2-0 win over Nottingham Forest in what seems certain to have been Cesc Fabregas's final match for the Blues.
It was the same result as Manchester United beat Reading to make it five wins out of five under caretaker boss Ole Gunnar Solskjaer.
Arsenal, the record 13-times FA Cup winners, won 3-0 at Blackpool, West Ham beat Birmingham 2-0 and Everton defeated Lincoln 2-1.
Saturday also saw Championship Bristol City beat top-flight basement club Huddersfield 1-0.
Elsewhere, in an all-Premier League clash, Brighton won 3-1 away to south coast rivals Bournemouth.
Second division Derby, managed by ex-England midfielder Frank Lampard, came from 2-0 down to draw 2-2 with Premier League strugglers Southampton, with Newcastle held 1-1 by second-tier Blackburn.
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....