High-flying Everton were knocked out of the FA Cup 1-0 by third division Oldham Athletic in the third round on Saturday, becoming one of four Premier League sides to go out to lower league opposition.
Birmingham City, Blackburn Rovers and Bolton Wanderers were the other upset victims, while Havant & Waterlooville carried the minor league flag into Monday's fourth-round draw after snatching a late 1-1 draw at third division leaders Swansea.
Holders Chelsea beat Queens Park Rangers 1-0 at home while last year's runners-up Manchester United went through with a 2-0 success at Aston Villa.
Everton are one of the form teams in the Premier League and their only two defeats in their last 17 games came at the hands of Manchester United and Arsenal.
However, Oldham added their name to that elite list thanks to Gary McDonald's 25-metre strike at the end of the first half, with Everton hitting the post in the last minute.
"To come to a Premier League ground against a team who are really flying at the moment was a great performance," Oldham boss John Sheridan told Sky Sports.
"I told the players to really enjoy the occasion, because things like this might not happen to them again. I was so pleased and proud of them."
Coventry, 17th in the Championship (second division) and in severe financial trouble, won 4-1 at Blackburn with two goals by Michael Mifsud and one each from Elliott Ward and Dele Adebola.
"Every one of us played with his heart and gave his best to ensure we got the result," Maltese striker Mifsud told Sky Sports.
HAVANT EQUALISER
Third division Huddersfield were also celebrating after a 2-1 home win over Birmingham, while Bolton, having rested Nicolas Anelka and most of the rest of their leading players, lost 1-0 at home to Sheffield United.
An 87th-minute equaliser by Rocky Baptiste earned Havant their replay against a Swansea side who had scored 20 goals in their previous six games.
Southern League midland division Chasetown, one of the lowest-ranked teams ever to reach the third round, led second division Cardiff City before losing 3-1, while Conference side Cambridge United also led at Wolverhampton Wanderers but lost 2-1 after an 88th-minute goal.
Chelsea were well below their best but went through with an own goal by QPR goalkeeper Lee Camp, while Manchester United beat Villa in the third round for the fourth time in six years thanks to goals from Cristiano Ronaldo and lively substitute Wayne Rooney in the last nine minutes.
In other all-Premier games Tottenham Hotspur, who beat Reading 6-4 last week, drew 2-2 with them at White Hart Lane, West Ham United and Manchester City drew 0-0 at Upton Park while Wigan Athletic won 3-0 away to Sunderland, whose performance left manager Roy Keane "ashamed."
Arsenal and Liverpool are both in action on Sunday, away to Burnley and Luton Town respectively, while struggling Newcastle United face a tough trip to Stoke City.
