Championship sides Ipswich Town and Hull City were dumped out of the Carling Cup on a night of upsets in the first round.
Paul Jewell's men were beaten at home by League Two outfit Northampton while Nigel Pearson's Hull were also humbled by League Two opposition in the form of Maccesfield Town.
New signing from Arsenal Jay-Emmanuel Thomas gave the Tractor Boys the lead at Portman Road, but goals either side of the break from Ben Tozer and Paul Turnbull stunned the hosts and put the Cobblers through to round two.
Maccesfield striker Emile Sinclair capitalised on some hesitation by Hull City goalkeeper Adriano Basso to put the Silkmen in front at the KC Stadium after 17 minutes.
Sinclair slotted home his second 14 minutes in the second half to effectively seal the game against a much-changed Tigers side.
In the battle for West Yorkshire bragging rights, Jack Compton gave Bradford City a shock lead after half an hour at Elland Road, only for Simon Grayson's Leeds to equalise a minute into the second half when Ramon Nunez's curling effort went in off the crossbar.
The Bantams re-took the lead 12 minutes later when Michael Flynn blasted the ball into the top corner. However, Leeds struck back and turned a thrilling game on its head with two goals in four minutes from Ross McCormack and Nunez again to squeeze through to the next round.
In another topsy-turvy local derby defender Mike Edwards struck first for Notts County against Nottingham Forest at the City Ground.
Goals from Lewis McGugan and Robbie Findley put Steve McClaren's men in front before County Substitute Craig Westcarr's tidy finish levelled matters with 16 minutes left and sent the game to extra time.
A spectacular effort from Lee Hughes put the away side in front eight minutes into extra time and that looked to have been enough before Wes Morgan's spectacular 25-yard strike drew Forest level again with the last kick of the game to send the match to penalties.
In keeping with the rest of the game the shoot-out swung this way and that. Lee Hughes had the chance to win the game for County but blazed over. Luke Chamber's successful spot-kick and another miss from County's Neal Bishop put the Championship side through at the expense of their neighbours.
Stephen Quinn's header just before the half hour looked to have been enough for Sheffield United and Danny Wilson on his return to old club Hartlepool. However, the home side drew level with just 10 minutes left through Antony Sweeney to send the game to extra time.
The match soon turned sour for Sweeney when he had to hobble off in extra time. As Hartlepool had used all their substitutes they had to end the game with 10 men, gamely hanging on for the penalty shoot-out.
Hartlepool's Sam Collins and Colin Nish missed the crucial spot-kicks to seal a 4-3 shoot-out win and send the Blades through to the next round .
Substitute Guillem Bauza put Exeter City in front against local rivals Yeovil and Chris Shephard sealed the game for the Grecians in stoppage time.
Hereford left it even later against Brentford at Edgar Street. Substitute Yoann Arquin was the hero in the second minute of stoppage time, putting the League Two side through at the expense of their League One opponents.
Reuben Reid put Oldham in front from the penalty spot after 24 minutes against Carlisle after Dean Furman had been fouled by Liam Noble.
Jon-Paul McGovern brought the Cumbrians back on terms 12 minutes after the break.
With neither side able to find a winner the game went to penalties. Josh Parker and Chris Taylor missed the crucial spot-kicks for Oldham to give Carlisle a 4-2 win.