The clock was approaching 100 minutes and the final whistle had long been blown when Bruno Fernandes stroked home yet another penalty to secure a wild win for Manchester United.
Chelsea also left it late in the English Premier League, but their goal deep into injury time could snatch only a draw from a perilous halftime position.
On another goal-filled day in a league where defences have temporarily gone missing, United beat Brighton 3-2 in a match that had pretty much everything to register their first victory of the campaign.
Chelsea then came from three goals down after 27 minutes to draw at West Bromwich Albion 3-3, with Tammy Abraham netting in the third minute of stoppage time.
Fourty-four goals were scored in the last round — a record haul since the division was reduced to 20 teams in 1995 — and it is already up to 15 from four games in this round with Everton winning at Crystal Palace 2-1 and Southampton at Burnley 1-0.
Five of the goals came at Brighton's Amex Stadium, and it should have been many more. Just ask Leandro Trossard, the Brighton midfielder who hit both posts and the crossbar in an uncommon triple.
With teammates Adam Webster and Solly March striking efforts against the bar and post respectively, Brighton hit the goal frame five times — a record since those statistics began in the 2003-04 season.
Still, Brighton looked like grabbing a draw few could have argued with when March equalised in the 95th minute to make it 2-2.
Yet there was still time for United to break forward from the restart, force a corner, and earn a penalty when Harry Maguire's goalbound header glanced off the flailing arm of Brighton striker Neal Maupay before being cleared off the line.
Referee Chris Kavanagh immediately blew the final whistle, only to be surrounded by United players calling for hand ball to be given. Kavanagh reviewed the incident on the pitchside monitor and awarded a penalty, much to the anger of Brighton's players who remonstrated.
When the chaos died down, Fernandes kept his cool to convert from the spot. After scoring a record 14 penalties last season, United are already up and running on the spot-kick counter for the 2020-21 campaign in the craziest way imaginable.
"We got away with one," United manager Ole Gunnar Solskjaer said. "Maybe one point we deserved; we didn't deserve more."
Thiago Silva had a Premier League debut to forget for Chelsea. The Brazil centre back coughed up a simple pass to let Callum Robinson run through and score his and West Brom's second goal on their way to an unlikely 3-0 lead at The Hawthorns inside half an hour.
Second-half goals by Mason Mount, substitute Callum Hudson-Odoi and then Abraham earned a point for Chelsea but it was a worrying display by a team which has been tipped to possibly challenge for the title after spending around $450 million on new players.
"We're still finding our way with new players and a lack of pre-season," Chelsea manager Frank Lampard said. "[Today] is part of the process of getting better."
Silva, who made his Chelsea debut in the League Cup in midweek, was named captain for the game but was substituted after 73 minutes.
Everton is top of the nascent standings with a maximum nine points, and has a stricter hand ball ruling to thank.
Richarlison converted what proved the winner against Palace from the spot in the 40th minute after Joel Ward became the latest player to fall foul of the newly adopted interpretation of defensive hand balls, when the ball struck his left arm after being headed on by Lucas Digne.
Because his arm was adjudged to have made his body unnaturally bigger, a penalty was awarded and Richarlison struck his effort into the top corner.
"I find it very disappointing that the game I love and believe in is being reduced to this level," Palace manager Roy Hodgson said. "Every week, games are being decided on so-called penalty decisions for hand ball which are definitely not hand ball."
Dominic Calvert-Lewin gave Everton the lead with his fifth goal of the season before Cheikhou Kouyaté equalised.
It's the first time Everton have won their first three games of a season since 1993.