Big boys take a beating

Luton claimed the biggest scalp of the day as they claimed a shock win at Norwich, while QPR can fully focus their attentions on their battle for Premier League survival after they were dumped out of the FA Cup by League One side MK Dons.

PA PhotosScott Rendell celebrates after

• Millwall 2-1 Aston Villa

Meanwhile, Arsenal and Manchester City both scraped through after narrow victories, while Everton snatched a late win to sink Bolton.

Luton Town became the first non-league side in 24 years to beat Premier League opposition as the Conference outfit defeated Norwich 1-0 at Carrow Road thanks to Scott Rendell's late finish.

The Hatters were preoccupied with defending for much of the contest, but substitute Rendell stunned the top-flight opponents with just ten minutes remaining as he found himself in the right place at the right time to steer home JJ O'Donnell's low cross.

Canaries boss Chris Hughton perhaps paid the price for starting the ineffective Simeon Jackson and Harry Kane up front, and even Grant Holt's late introduction could not produce a breakthrough. The unheralded visitors were reasonable value for their success, though, creating a number of opportunities over the course of the contest as they also edged the possession statistics.

Where Holt's introduction did not have the desired effect, Luton manager Paul Buckle's tactical change certainly did. Rendell had been on the pitch just six minutes when he scored the historic winner, blasting past Declan Rudd to write his name into cup folklore.

Relegation-threatened QPR suffered major embarrassment as they were beaten 4-2 by League One promotion contenders Milton Keynes Dons.

Rangers manager Harry Redknapp could have been forgiven for fearing that things were not going to go his side's way early on after Armand Traore deflected a low cross - that had perhaps first been touched on by Dean Lewington - beyond goalkeeper Robert Green and into his own net.

Things got worse for Redknapp's rotated side as a poor mistake from Anton Ferdinand allowed Ryan Lowe in behind the defence to make it 2-0 shortly before half-time. Ryan Harley and Darren Potter then scored similar close-range strikes six minutes apart to leave the West London club, somewhat shamefully, four goals adrift in front of their own fans.

The scoreline was not entirely representative of the full 90 minutes' play but QPR only made something of their great number of chances in the closing stages, as Jay Bothroyd latched onto Bobby Zamora's flick on to get on the scoresheet, having already been guilty of a number of misses earlier in the contest.

Pablo Zabaleta scored in the 85th minute to send Manchester City into the fifth round with a 1-0 victory over Stoke.

In a repeat of the 2011 final, when City also won 1-0, the Premier League champions dominated the action primarily through the dual threats of Carlos Tevez and David Silva, although Stoke had a goal from Ryan Shawcross ruled out for offside.

City finally broke through five minutes from time when Silva's late break forward gave Sergio Aguero the chance to play the ball across the area, and Zabaleta arrived at the back post to turn it goalwards.