Striker Robbie Keane scored twice to steer Tottenham Hotspur to a 4-0 win at Fulham while Manchester City came back to beat Preston North End 3-1 to reach the FA Cup quarter-finals on Sunday.
In two copycat strikes, Keane volleyed home superbly from the edge of the area in the seventh and 69th minutes at Craven Cottage, both times supplied by Egypt striker Mido.
Bulgarian Dimitar Berbatov came off the bench to turn it into a rout, scoring in the 78th and 89th, and Fulham's misery was complete when Italian substitute Vincenzo Montella was red-carded at the end.
"Fulham away is always difficult but you saw right from the first minute that our boys knew what was expected of them -- we wanted to go to the next round," Spurs manager Martin Jol told Sky Sports.
"It was very important for us...I think it's the most important Cup in Europe."
Fulham manager Chris Coleman pinpointed his side's problem, saying: "Defending, end of story. We can't defend like that...I'm bitterly disappointed with the way we gave the goals away, certainly the first two. After that, our heads dropped."
Late goals gave City their comeback win in the fifth round at Deepdale and a place in Monday's draw.
A shot by Greek striker Georgios Samaras, initially credited with the goal, was deflected in by defender Matthew Hill for 2-1 and Irish midfielder Stephen Ireland added the third.
Manchester United and Arsenal face replays after Saturday's ties, but Chelsea cruised into the last eight with a 4-0 romp at home to second division Norwich City.
United will visit Reading on February 27 after a 1-1 draw at Old Trafford while Arsenal will be at Ewood Park the following night after a 0-0 draw with Blackburn Rovers at the Emirates Stadium.
Watford and second division Plymouth Argyle are in the last eight while Middlesbrough face a replay at the Hawthorns after a 2-2 draw with second division West Bromwich Albion.
The final is scheduled to be played at the new Wembley Stadium on May 19.
