Phillip Cocu felt that Derby County’s Sky Bet Championship clash at West Bromwich Albion on Wednesday evening was settled by the hosts being better in the fine details which decide games.
A goal in each half from Grady Diangana and Dara O'Shea secured a 2-0 win and all three points for the Baggies at the Hawthorns.
The result saw Derby taste defeat in the Championship for the first time in seven matches, having won five and drawn one of their previous six outings to burst into play-off contention.
Youngster Louie Sibley was also sent off late on alleged violent conduct, although replays suggested the decision was harsh.
Speaking to RamsTV after the game Cocu said: “I think you could see and recognise that is was a big game for West Bromwich Albion; a crucial game in the fight for promotion.
“They played a good game, they have some quality players but also they were really aggressive and pushed us.
“For most of the game it was quite equal. It went up and down with both teams having good periods.
“Details decide the game and finally they were better in that than us, especially for the second goal. It was a set play and we lost our marker to score, which made it game over. This was an important lesson for us.
“We have to accept the defeat today against a strong team and focus on Saturday against Brentford.”
Derby’s starting line-up against the Baggies had three players from the club’s Academy, while a further five came off the bench during the second half.
Jordan Brown and Jamal Hector-Ingram made their professional debuts off the bench and Cocu was pleased with how all the youngsters performed against one of the division’s top sides.
He added: “It is a big experience for the youngsters to play in a game like this.
“We don’t have a lot of numbers in the squad because we have a few injuries and suspensions, so it is up to the young guys.
“The challenge is bigger against the top teams, their team is more experienced and bigger, but it is an important step for them in their development and we have to be proud in their performance.”
Cocu was not happy with the sending off of Sibley late on.
The 18-year-old is facing a three-game ban but the Rams’ boss says the red card will be appealed.
He said: “I don’t think that’s a suspension, so I think if they will take a closer look then it is definitely not a red card.
“He is not kicking their player. That is a big frustration because he does not deserve a suspension and we will appeal it.”
Derby return to Championship action on Saturday against another side fighting for automatic promotion in Brentford at Pride Park Stadium (12:30pm kick-off).