The action started with the lunchtime game between Championship side Brighton and Newcastle United of the Premier League. The later have been struggling for league points and the sale of striker Demba Ba has not gone down well on Tyneside. (The fact that he scored double in his Chelsea debut at Southampton won't have lightened the mood for Toon fans).
Brighton ran out worthy winners as Andrea Orlandi scored a delightful opener after the half-hour mark before the Premier League Magpies suffered a further setback when Shola Amoebi was sent off for a second bookable offence.
Substitute Will Hoskins sealed victory late on, rolling in David Lopez's pass. The result adds to the mounting pressure on Toon boss Alan Pardew.
The 3.00 pm kick-offs saw some fanatstic games, none more so than Macclesfield Town's win over Championship leaders Cardiff City. The Moss Rose has never seen a bigger upset with Macc coming from behind to win 2-1. The non-league side now get the chance of a finacial bonus from a fourth round tie with one of the big boys.
Like Newcastle, Wolves have been struggling at the wrong end of the table and defeat at Luton wasn't in the script.
Alex Lawless was the Conference team's hero and his winner piled more pressure on Wolves boss Stale Solbakken.
Wolves were punished when defender Kevin Foley messed up a clearance, allowing Jon Shaw to head down for Lawless to volley home on 46 minutes.
Four-time winners Wolves created little in response as the Hatters deservedly ran out as surprise winners.
Oldham's FA Cup pedigree was top class in the 90s with two FA Cup sem-finals (both went to replays) against Manchester United. Since then the Latics have dropped from the Premier League to League 1 but their FA Cup pedigree has not deserted them.
They reached last season's 3rd round before losing at Anfield to Liverpool after leading and they reached this season's fourth round with a great fight back at Nottingham Forest.
Oldham ran out 3-2 winners after trailing their Championship opponents at half-time.
Matt Smith turned the ball into his own net to gift Forest a first-half lead.
But Robbie Simpson followed up a brilliant 25-yard strike with a deft header to make it 2-1 to the Latics.
Jose Baxter's stunning free-kick, after Danny Collins was sent off, secured a sensational victory despite Billy Sharp's late strike.
Oldham, 19th in League One and just five points above the relegation zone, fully deserved their incredible win, which puts them into the fourth round for the first time in five years and leaves new Forest manager Alex McLeish still seeking a first win after three games in charge.
Manchester United led at West Ham through Tom Cleverley, but Sir Alex Ferguson was forced to bring the likes of Robin Van Persie, Ryan Giggs and Valencia off the bench to secure a last gasp leveller after West Ham had come from behind to lead 2-1 with 90 minutes up.