Premier League sides West Ham and Fulham crashed out of the Carling Cup at the third-round stage at the hands of Football League opposition.
Gianfranco Zola's Hammers were sent packing by Watford at Vicarage Road as goalkeeper Jan Lastuvka missed a cross and the ball went in off Hayden Mullins for an own goal (70) as the Hornets triumphed 1-0.
It was the same scoreline at Turf Moor as a goal from substitute Jay Rodriguez two minutes from time handed Burnley victory over Fulham.
League Two will have a representative in the fourth round after Rotherham piled more misery on Championship strugglers Southampton with a 3-1 victory.
Arsenal's next generation gave a display of precocious talent in a 6-0 home win over Sheffield United, with Carlos Vela the star of the show.
Established first-teamer Nicklas Bendtner (31, 42) finished off clever assists from Vela and Aaron Ramsey to put the Gunners two up before Vela made it three (44) with a lovely curling effort.
The Mexican then grabbed his second by leaving Paddy Kenny on his backside before calmly slotting in his second (50) and 16-year-old Jack Wilshere got in on the act with the fifth (57). Fittingly, Vela had the last word by completing his hat-trick three minutes from time.
Manchester United and Liverpool both progressed safely - Sir Alex Ferguson's side beating Middlesbrough 3-1 while their big rivals saw off Crewe 2-1. Cristiano Ronaldo marked his first start of the season with the opener at Old Trafford when he headed in Ryan Giggs' corner (25).
Brad Jones kept Boro in contention with some fine saves before Adam Johnson shocked the home crowd by drawing the visitors level with a shot from the edge of the box (56).
But they found themselves a man down when Emanuel Pogatetz was shown a straight red card for a bad foul on Rodrigo Possebon, who was carried off the pitch with what looked a bad injury and Ryan Giggs and Nani scored late on.
Swansea emerged victorious in the most keenly-contested match of the evening with a 1-0 win over bitter rivals Cardiff.
Jordi Gomez grabbed the only goal of the game with a deflected free-kick which Peter Enckelman could not keep out (57).
Andy Robinson scored an injury-time winner as Leeds defeated fellow League One side Hartlepool 3-2 at Elland Road.
Daniel Agger opened the scoring at Anfield when he fired in a free-kick after 15 minutes. But Crewe showed they would be no pushovers by equalising through Michael O'Connor (25) after debutant keeper Diego Cavalieri had parried Calvin Zola's header.
There was to be no fairytale victory for the League One side, however, as Lucas headed in Jermaine Pennant's cross (58) for what proved the winner.
Sunderland escaped an upset to defeat League One strugglers Northampton 4-3 on penalties after a 2-2 draw. Colin Larkin (20) opened the scoring and Luke Guttridge to make it two nine minutes from time.
Striker Anthony Stokes scored twice in the last four minutes - his second coming in injury time - but Sunderland had to play the additional 30 minutes with 10 men after Nyron Nosworthy went off injured with no more substitutes available.
Mark Hughes missed Northampton's first spot-kick and although Stokes hit the crossbar Leon Constantine was denied by Marton Fulop with the final kick.
It was the same story for Stoke as they were held to a 2-2 draw by Reading before coming through 4-3 in a shoot-out.
Stoke's Vincent Pericard (nine) and James Henry (penalty) traded first half goals before the Premier League side went ahead again through Mamady Sidibe (50) before Henry (75) scored his second. However, the youngster missed his penalty - as did Leroy Lita - in the shoot-out as Stoke came out on top.