It looked destined for penalties but a late 99th minute goal from Marc Bola sends Watford through to the second round.
Crawley fought hard for so, so long, and Vito Mannone performed admirably for most of the match, keeping out numerous shots.
But Watford deserved to prevail, and of all the players most unfortunate you have to feel some sympathy for Luca Kjerrumgaard whose disallowed goal and shot which hit the woodwork did nothing to give them breathing room.
It took Marc Bola's last minute intervention to settle the tie.
Bolton pay dearly after Xavier Simons loses his head to put them a man down.
After being pulled back by Harry Gray, Simons repaid the favour by lashing out with a punch. The Wednesday players were up in arms and things got heated but the Owls men would have the last laugh as Simons was given his marching orders.
Jamal Lowe came on the field and scored from Barry Bannan's ball.
A win. Barry Bannan involved in the goals. The feel-good factor is in full flow at Hillsborough now.
Taty Castellanos and Jarrod Bowen combine to put the game to bed for West Ham and knock out Portsmouth despite a decent performance from the visitors.
After a first half comeback from 1-0 down, West Ham scored a third and final goal in the 50th minute after Bowen sets up Castellanos for a superb header.
Portsmouth played well but not well enough to surpass the Hammers' talented squad.
A force to be reckoned with in the upcoming Championship campaign? It's certainly looking so.
GOAL: Watford 1-0 Crawleypublished at 17:02 BST 8 August
17:02 BST 8 August
Marc Bola (90 + 9 mins)
99th minute. Ouch.
Neither Watford nor Crawley players can get a hold of the Hornets' corner until it falls to Marc Bola, who lets loose a thunderous strike that rattles right past the 'keeper.
The fans were braced for penalties but it looks like Watford have just done enough.
Leicester are through to the second round of the EFL Cup, thanks to that early goal by defender Caleb Okoli.
Northampton fought hard, but it just wasn't enough on the day.
The Foxes thought they had doubled their lead in the second half thorough Liam Cullen, especially because of how long it took for the linesman to raise his flag.
But it doesn't matter now. If Leicester are to get back to where they were a decade ago the journey begins here with a decent first round win the EFL Cup.
August Priske's first-half goal puts Birmingham through to the second round.
The Swans dominated on the shot counter, with 14 to Blues' mere six. But only two were on target and their lack of clinical shooting inevitably loses them the game.
Though for Birmingham, their summer remains undefeated. Not a bad way to enter the new Championship season next week, ey?