Third tier Leeds knocked Manchester United out of the FA Cup in one of the competition's most famous upsets on Sunday while defending champion Chelsea outplayed Watford in a 5-0 victory to reach the fourth round.
Arsenal came from behind to win 2-1 at West Ham with two late goals in a five-minute spell by Aaron Ramsey and Eduardo da Silva.
Jermaine Beckford's 19th minute strike at Old Trafford gave League One leader Leeds a memorable victory at a ground where it had not won since 1981.
Leeds became the first team to knock United out in the third round since Harry Redknapp's Bournemouth in 1984, two years before Alex Ferguson took charge at Old Trafford. United has won the trophy five times under Ferguson and holds the record of 11 FA Cup triumphs.
Ferguson was scathing about the performance from the Premier League champions for the past three seasons.
"I didn't expect that," Ferguson said. "I'm shocked at the performance. Leeds fought like tigers, you would expect that when they come to Old Trafford for an FA Cup tie. They are human beings, they can always surprise you.
"Beckford has got a lot of pace up front and we were caught napping, really. It was a bad goal for us to lose but the whole performance was bad."
Ferguson also criticized referee Chris Foy for playing only five minutes of injury time even though there were frequent stoppages in the second half.
"The referee gave five minutes of injury time - that is an insult to the game and the players out there," the United manager said.
While United floundered at home, Chelsea raced into a 3-0 lead at Stamford Bridge inside the first 22 minutes. Daniel Sturridge scored his first two goals for the club, Watford's John Eustace put the ball into his own net and Florent Malouda and Frank Lampard added the others.
West Ham went ahead a minute before halftime at Upton Park when Alessandro Diamanti beat Arsenal's offside trap to run clear and fire home via the inside of the post.
Ramsey equalized in the 78th minute after good approach play by Alex Song and Carlos Vela and 10-time champion Arsenal captured a fourth round spot through Da Silva's header in the 83rd minute from a leftwing cross by Vela.
A meeting of two League Championship clubs, Sheffield United and Queens Park Rangers, ended 1-1.
In Sunday's late game, Wolves needed a 77th minute strike from Matthew Jarvis to beat Tranmere 1-0. The third round match between League Two Notts County and non-league Forest Green was called off because of a frozen pitch.
There were no major upsets in Saturday's third round games, although Liverpool was held 1-1 by second tier Reading, Portsmouth drew 1-1 with Coventry and Birmingham finished 0-0 with Nottingham Forest.
