Record 11-time FA Cup winner United almost took the lead in the 15th when Park Ji-sung lunged at the far post to get to a cross by Nani. The South Korea midfielder directed his shot on target but goalkeeper Stephen Bywater made an instinctive save to redirect the ball across goal and out for a corner.
Nani eventually got the opening goal with a run and shot at the edge of the area but Ronaldo had an effort ruled out because of offside in the 37th, although the linesman raised his flag so late that he was already celebrating with his teammates.
"We were celebrating and we think we've scored," United captain Ryan Giggs said. "But we just got on with it and our attitude was good after that."
Gibson, who scored his first goal for United in last month's third-round match at Southampton, made it 2-0 with an 18-meter (yard) shot and Ronaldo headed in from a corner for his 14th goal of the season.
Addison's header and Teale's shot made things slightly uncomfortable for United, but Welbeck completed the win with a curling right-foot shot across the goalkeeper and inside the far post.
With both Everton and Aston Villa firmly ensconced in the top six of the Premier League, their fifth-round match was expected to be closely fought and there were three goals, two penalties, two handballs and four yellow cards in the first 25 minutes at Goodison Park.
Jack Rodwell put Everton ahead in the fourth minute from a close-range rebound after Stilian Petrov had blocked the ball on the line with his hand, but James Milner made it 1-1 with a penalty just four minutes later after Tony Hibbert was booked for fouling Gabriel Agbonlahor in the area.
Everton midfielder Tim Cahill was given a yellow card for a handball and his Villa counterpart, Steve Sidwell, was then booked for ending Victor Anichebe's burst into the area with a mistimed sliding tackle.
Mikel Arteta scored the resulting penalty to make it 2-1 in the 24th and Petrov, who could easily have been sent off for his earlier handball, was booked for a foul in the middle of the field.
Cahill rounded off the scoring in the 76th, tapping in after both Villa's central defenders failed to clear Anichebe's cross from the left.
"We won't be getting carried away," Everton manager David Moyes said of his team's chances in the next round. "There will be no wild predictions. But the team has been very good, very strong. They want to beat whatever is put in front of them.
"They should be excited. They are enjoying their game."
Everton will host West Ham or Middlesbrough in the next round, while Chelsea, the only team to make it into the quarterfinals on Saturday after it won 3-1 at second-tier Watford, will be at Blackburn or Coventry next.
Arsenal hosts Cardiff in a fourth-round replay on Monday, with the winner set to face Burnley in the fifth round. The winner of that match will meet Hull or Sheffield United in the quarterfinals, which are scheduled for March 7 and 8.
There are four fifth-round replays scheduled for the week starting Feb. 23 after draws in Saturday's matches. Coventry will host Blackburn following a 2-2 draw, West Ham goes to Middlesbrough following a 1-1 draw, and Fulham hosts Swansea. Hull and Sheffield United meet again, too, after they drew 1-1.
(Agencies via Shanghai Daily February 16, 2009)
