Vorm, wrong-footed by Vertonghen's intervention, was prone on the turf as the ball rolled through his out-stretched arms to Firmino, who couldn't miss from on the goal-line.
The Belgian defender caught his Brazilian opponent in the face while competing for the ball.
It was the visitors who were out of the blocks the quickest, and they almost went ahead in the opening minute when Roberto Firmino touched in a cross from the right and it beat Michel Vorm in the Spurs goal.
Liverpool, meanwhile, host Paris Saint-Germain at Anfield in Europe's elite competition prior to welcoming Southampton next Saturday - where they will look to take their unbeaten run to six games.
"I have no clue what exactly happened", said Klopp.
"I didn't see it back, I didn't see anything back from the game".
"I don't like the situation; it's not that I like to say to Fabinho, who is full of energy and desire and wants to be involved, "you are not involved this weekend".
Mother and child killed as Florence swamps Carolinas
That's enough to fill the Chesapeake Bay or cover the entire state of Texas with almost 10 centimetres of water, he calculated. More than 60 people had to be rescued in another town as a cinderblock motel collapsed at the height of the storm's fury.
But Klopp, a victor at Wembley for the first time, won't be complaining after securing a rare away victory at one of their top six rivals, proving they are likely to be the biggest threat to champions Manchester City. "It was something with his eye", Klopp said in his post-match press conference. It was an intense job to do and the boys did it.
It is only the third time in their history that they've opened up a top-flight season with five wins on the spin and although it's early days, plenty of fans and pundits believe they're the main contenders to Manchester City for the title. Over 85 minutes we were really dominant.
"If you compete and they were better, you say congratulations, but I think we can not compare".
But Tottenham were careless from start to finish and they paid the price in the 39th minute.
"The performance today was better than the result".
"That was a tough game, man!"
"We had quite a good session yesterday, couldn't do too much because some of them came off the plane".