Barnet and Newport provided the biggest shocks in the third round as they knocked out Sheffield United and Leicester respectively.
Holders Chelsea, plus fellow big guns Manchester City, Tottenham, Arsenal and Manchester United all reached the fourth round, but five top-flight sides made their exits.
Here, Press Association Sport takes a look at five things we learned from this weekend's third-round ties.
Barnet fly flag for minnows
Barnet kept FA Cup romance alive and kicking by stunning Sky Bet Championship promotion-chasers Sheffield United at Bramall Lane. Shaq Coulthirst's first-half penalty and goalkeeper Mark Cousins' superb late save to deny Leon Clarke were enough to blunt the Blades and ensure the Bees, in 15th place in the Vanarama National League, are the only non-league side in the hat for the fourth round draw.
Giant-killing is no lost art
All neutrals love a giant-killing and Barnet were not the only lower league side to bloody the nose of a more fancied club and dump them out of the competition. Newport knocked Leeds out of the competition last season but went one better by stunning Premier League club Leicester in a 2-1 win at Rodney Parade. Cardiff came unstuck at League One strugglers Gillingham, basement club Oldham stunned Fulham at Craven Cottage and Huddersfield were knocked out by Bristol City. Another top-flight side, Bournemouth, lost at home to Premier League rivals Brighton.
Video assistant referees in spotlight
A video assistant referee (VAR) was used in nine of this weekend's ties and the technology made some crucial interventions. Burnley were denied a penalty after a VAR referral in their home win against Barnsley and another in Manchester United's victory over Reading led to confusion when Juan Mata's 20th-minute 'goal' was ruled out, apparently for offside, before a penalty was awarded. VAR was consulted before Grimsby defender Andrew Fox's early dismissal in his side's defeat at Crystal Palace and also for Aleksandar Mitrovic's saved penalty in Fulham's shock defeat to Oldham.
Farewell from Fabregas?
Chelsea launched their defence of the world's oldest knock-out trophy by beating Nottingham Forest at Stamford Bridge, where Cesc Fabregas had a first-half penalty saved in possibly his last game in English football. The 31-year-old, who has made a combined total of 501 appearances for Arsenal and Chelsea, is reported to be joining Thierry Henry's Monaco. The Spanish midfielder was given a standing ovation when substituted and was the last player to leave the pitch after returning at the final whistle to wave goodbye.
Upset not on Cards for Tyler
Veteran commentator Martin Tyler swapped his microphone for a tracksuit as he took his place in Woking's dug-out in their home defeat to Watford. The 73-year-old, better known as the voice of Sky Sport's football, became a non-paid member of Woking boss Alan Dowson's coaching staff following the latter's appointment in May. Life-long Cards fan Tyler was assistant manager for the day, but could not inspire the National League South side to an upset as Watford ran out 2-0 winners.