Barnsley boss Lee Johnson has promised a major overhaul at Oakwell if he is not sacked after his side crashed 1-0 at Altrincham in the FA Cup first round.
Damien Reeves was Altrincham's hero, firing a second-half winner to send Johnson's League One strugglers spiralling to a sixth straight defeat.
"I'm angry with the situation," Johnson said. "We need to shake it up and if I'm still here, as people obviously keep questioning, I'll be the one to shake it up for sure."
Eastleigh produced another giant-killing as Ben Strevens' 75th-minute penalty clinched a 1-0 victory at 10-man Crewe, who had goalkeeper Ben Garratt sent off.
Boss Chris Todd said: "We have to believe we're capable of doing something this season. The league is our priority, but the FA Cup is brilliant for everybody involved - everybody is buzzing."
Bristol Rovers tumbled out of the competition as Ryan Blake's 77th-minute strike from distance gave Chesham a memorable 1-0 win.
United manager Andy Leese admitted: "It's the greatest day of my footballing life.
"All week we had been telling the lads to go out and make a name for themselves and they have done just that.''
Elliott Frear struck in time added on to clinch Forest Green a 2-1 home win against AFC Wimbledon, but fellow non-league sides Staines Town and Wealdstone were both hit for six.
Orient despatched Staines 6-1 and Wealdstone went down 6-2 at home to Colchester, while St Albans were thumped 5-1 at Grimsby.
James Mulley's strike in the fourth minute of injury time ensured Maidenhead a replay after a 1-1 draw at League One outfit Port Vale.
Curtis McDonald's 90th-minute header helped Brackley to a 2-2 draw at home to Newport, Braintree also earned a replay, with Kenny Davis levelling in a 1-1 result with Oxford, as did Aldershot after a goalless stalemate against Bradford.
Whitehawk ran out 5-3 winners against Lincoln, Welling progressed courtesy of a 2-0 win at minnows Barwell, Stourbridge upset hosts Dover 2-1 and Northwich and Boreham Wood drew 1-1.
Basingstoke lost 1-0 at Cambridge, Doncaster beat Stalybridge 2-0, Worcester went down 3-0 at Sheffield United and Millwall ran out 3-1 winners against AFC Fylde.
Wigan, Cup winners in 2013, slumped to a 4-0 defeat at Bury, Barnet upset Blackpool 2-0 and Northampton pulled off a surprise 2-1 win at Coventry.
League Two leaders Plymouth lost 2-0 to Carlisle at Adams Park and Stevenage were surprise 3-0 winners against League One high-flyers Gillingham.
Wycombe sauntered into the next round with a 4-0 victory at Halifax while Shrewsbury and Yeovil also booked their second round spot after eking out 1-0 wins at Gainsborough and Maidstone, respectively.
Rochdale, Walsall and Scunthorpe all progressed courtesy of home wins against Swindon, Fleetwood and Southend, respectively and Peterborough stunned Burton with a 3-0 away win.
Elsewhere, Accrington edged out York 3-2, Hartlepool squeezed past Cheltenham 1-0, Portsmouth beat Macclesfield 2-1 and Luton won 2-1 at Crawley.
Ties between Dagenham & Redbridge and Morecambe and Mansfield and Oldham ended goalless.