* Off-key holders still in hunt for third Cup win in a row
* Orient through to fifth round after another upset
* Crawley first minor league club through for 17 years
Holders Chelsea needed a late equaliser by Salomon Kalou to snatch a 1-1 draw that kept them in the FA Cup after a Louis Saha header had put Everton on course for a fourth-round upset at Goodison Park on Saturday.
At the other end of the soccer spectrum, minor league Crawley Town advanced to the last 16 for the first time after they beat League Two (fourth division) Torquay 1-0 away despite having two penalties saved.
Matthew Tubbs got the only goal late in the first half for Crawley, who knocked out league clubs Swindon Town and Derby County in the last two rounds, though Tubbs was one of the players to have a penalty saved by Scott Bevan in a match where both sides had a man sent off.
Crawley, heavily funded and on course for promotion to the Football League, are the first minor league team into the last 16 since Kidderminster Harriers in 1994.
"It was the least we deserved. We dominated for long periods," Crawley manager Steve Evans told BBC Radio 5-Live.
"We said we could win, not many people gave us a hope here but we did."
Leyton Orient, struggling at the wrong end of League One (third division), pulled off a second successive upset win when, having knocked out Norwich City away from home in the last round, they won 2-1 at Championship (second division) promotion-chasers Swansea.
In two more of the weekend's five all-Premier League ties, Aston Villa beat Blackburn Rovers 3-1 while Bolton Wanderers drew 0-0 at home with Wigan Athletic.
Birmingham City, who reached the League Cup final in midweek, came from 2-0 down to beat Championship side Coventry City 3-2 and go into Sunday's fifth-round draw.
Eleven-times winners Manchester United, with some of the biggest names on the bench, visit League One Southampton later on Saturday in a repeat of the 1976 final when then-second division Southampton claimed a shock 1-0 win.
Chelsea, bidding to be the first team to win the FA Cup in three successive seasons since Blackburn Rovers in 1884-86, played a full-strength team but looked flat all day and only good goalkeeping by Petr Cech kept them in the game.
Everton, unbeaten against Chelsea in the league in five games, took control in the second half and led after 62 minutes when Saha powerfully headed in a corner.
Chelsea boss Carlo Ancelotti reacted by sending on Kalou in the 70th minute and five minutes later the Ivorian had equalised when he finished off a swift counter-attack.
"The result was good, we were 1-0 down and it wasn't easy to come back into the game," Ancelotti told the club's website (www.chelseafc.com).
"Everton put strong pressure all the time on the pitch, used a lot of long balls, they were very dangerous on set-pieces and scored on one. It was a difficult game but we showed good spirit."
When asked about his club's bid for Liverpool striker Fernando Torres, the Italian said: "I don't know, we will have to wait."