Craig Levein has urged his Scotland players to use a sense of injustice following their 2-1 defeat to Wales to drive them on to victory in Belgium.
A first-half opener from James Morrison meant the Scots were on course for their first World Cup qualifying Group A win in the Cardiff City Stadium last night.
But they were sunk by a late double from Gareth Bale as the home side fought back to claim a dramatic first victory of the Chris Coleman era.
However, the outcome could have been very different had a Steven Fletcher goal - when the visitors were still leading with 15 minutes to go - been allowed to stand.
The assistant referee ruled that Charlie Adam's cross had swung out of play, despite television footage suggesting otherwise, leaving the Scots empty-handed and needing a victory in Brussels on Tuesday night to save their campaign.
Levein said: "It is a disappointment. We have all been in football long enough to understand that things don't always go your way.
"We have had some hammer blows and this is the latest one.
"We have got an honest, hard-working group of boys who feel a bit aggrieved about what happened and we will try to use that for Tuesday.
"The only we thing we can do is go to Belgium and try to win the game.
"I feel an injustice but the important thing is that we react in the right manner.
"We have got Belgium and it makes it more difficult because we need to win in Belgium now."
There was also debate afterwards about the penalty which sparked the Welsh comeback, which was won and converted by Bale after going down in the box under pressure from Shaun Maloney.
Levein said: "I've no complaints. I couldn't see it completely myself but certainly our players didn't make an awful lot of noise about it and it very well could have been a penalty.
"The players were very quiet as you can imagine, there wasn't much said at all.
"I'll have a chance to have a look at it but we all know the game is finished now and whether the officials have made one, two or three mistakes, it is not going to help us now."
On Bale's performance overall, Levein added: "I thought in the first half we coped with him reasonably well.
"We stopped him getting the ball. That was the plan, to stop him getting into dangerous areas and getting possession of the ball. I thought we managed to do that quite well.
"In the second half, I felt the longer the game went on at 1-0, he started to wander a bit, take up different positions on the field and that is a little bit more difficult to stop.
"But he is a fantastic player and he did cause problems for us.
"I thought we had contained him reasonably well, but later in the game he became an issue for us."
Fletcher was back in the Scotland side, ending his international exile, having recently resolved a long-running dispute with Levein stretching back to February 2011.
The manager was pleased with the contribution of the Sunderland striker, albeit he believes the positives on the night were tempered by the result.
Levein said: "He set up James Morrison's goal and another good chance in the first half.
"Then, if the goal stands, he gets a goal here. So I was really pleased with his performance.
"We had some really good performances but the fact that we didn't get a victory takes the gloss off everything."