Sheffield United pulled off the first major shock of FA Cup third round weekend when the third-tier English side triumphed 3-0 at Premier League outfit Queens Park Rangers on Sunday.
Manchester United started their FA Cup campaign with a hard-fought 2-0 victory away to third-tier Yeovil Town.
With United sitting nine points behind both Chelsea and Manchester City in the Premier League, this competition is their most realistic chance of winning silverware this season.
James Milner celebrated his 29th birthday by scoring twice as Manchester City fought back to beat Championship side Sheffield Wednesday.
Rangers, struggling near the foot of the Premier League table, had more misery heaped on them at their Loftus Road home, with a second-half double from winger Jamal Campbell-Ryce sealing the emphatic victory for League One's sixth-placed team.
Yet on the weekend when the minnows of England's lower leagues traditionally go hunting for Premier League scalps, Crystal Palace, under new manager Alan Pardew, comfortably sidestepped any possible embarrassment with a 4-0 stroll at little Conference side Dover Athletic.
Another Premier League team, Sunderland also prevailed 1-0 against the Championship's Leeds United, a goal from Patrick van Aanholt ensuring the result mirrored that of the teams' famous 1973 Cup final.
Decade of woe
QPR entered their match with some trepidation, having won only two FA Cup games in a decade and lost their previous Cup encounter with a League One side when beaten by MK Dons.
So this match against confident visitors who had already despatched Premier League teams Southampton and West Ham en route to the League Cup semi finals again had an ominous look for them once Marc McNulty, United's top scorer, struck after 36 minutes.
Campbell-Ryce cashed in four minutes after half time when Rangers' defence failed to deal with a straightforward corner and he bundled the ball home from a yard out.
Then he sealed the handsome win, making a nonsense of the 34-place gap between the two sides as he rounded the keeper to roll in the third in the game's dying moments.
Pardew's return to the club where he most famously made his name as an FA Cup hero during Palace's run to the 1990 final was given a stirring lift-off with an first half double from defender Scott Dann and second half goals from Gayle and Kevin Doyle.
A full-house packed into Dover's little tree-lined Crabble Athletic ground and a pitch which cut up easily promised an uncomfortable afternoon for Palace but Dann's 10th minute volley calmed any nerves for the former Newcastle boss Pardew.
Sunderland's fixture with Leeds transported everybody back to the historic Wembley final when Ian Porterfield's goal and Jim Montgomery's goalkeeping heroics enabled then-second division Sunderland to earn one of the most famous Cup triumphs over the then all-conquering Yorkshire side.
Forty-two years on, the roles were reversed, with Sunderland now the top tier side and Leeds the second division strugglers in the Championship - but the result was exactly the same.
The modern-day Porterfield turned out to be Dutchman van Aanholt, who struck the 33rd minute winner, but Leeds came desperately close to equalising in injury time when their captain Liam Cooper's header hit the post.
Manchester United and Manchester City were in action in the mid-afternoon kickoffs.