Gianfranco Zola admits Watford have to improve before their Championship campaign begins after needing extra-time to beat League Two Wycombe.
A Chris Iwelumo winner in the 110th minute was all that separated Watford and Wycombe after the Capital One Cup tie finished 0-0 at 90 minutes at Vicarage Road on Saturday.
Zola said: "It took a long time but it came eventually and that is the most important thing.
"Wycombe made it difficult for us because they didn't allow us much space, especially up front.
"But to be honest, in the first half especially, we were too slow moving the ball and there were also a lot of mistakes individually. Therefore we didn't get the rhythm we wanted and that was the main reason why we found it difficult in the first half.
"We need to improve, the players know that, and we will take a lot of important things from this game.
"I was looking for a game like this. So far our friendlies have been very good but sometimes you need something like this to improve.
"We need to take it to a higher level because on Saturday it will be tough."
There was a lively start and finish to the game, but on the whole it was largely uneventful.
Jonathan Hogg headed narrowly wide for Watford early on and minutes later, former Arsenal goalkeeper Manuel Almunia made up for his initial error by saving from Wycombe striker Richard Logan.
Wanderers stopped the Hornets from playing the passing football Zola is trying to implement but both sides struggled to create chances throughout the match.
New Watford signing Matej Vydra, who has joined on loan from Udinese, was one of the few highlights and created the chance which decided the contest, leaving Iwelumo to bundle home from close range in the second half of extra-time.
Zola said: "He is young and has a lot of potential. He can be a very good player for this club."
Wycombe manager Gary Waddock was pleased with his side's display.
He said: "It was a very good performance by our lads.
"Probably one mistake, or error, has cost us and they punished us for it. Overall I thought we played extremely well.
"Richard Logan had an opportunity in the first half when their keeper made a fantastic save. I thought the ball might have spun the other way and gone in.
"We restricted them, we stopped them playing. The organisation and discipline from the players was good. We've got to take that into the league campaign."
Wycombe had a late penalty appeal for handball and Waddock added: "I thought it was a definite penalty from where I was. The referee was up with play - sometimes you get them, sometimes you don't.
"But the Watford players knew they had been in a game. We kept battling and plugging away - it is just a mistake has cost us in the end. It's a positive day but unfortunately the result didn't go our way."