Northern Ireland manager Michael O'Neill says his side's last-gasp 2-1 Nations League defeat by Austria at Windsor Park is "a bitter blow".
Valentino Lazaro's spectacular injury-time finish meant Northern Ireland lost all four games in the new competition.
"For the majority of the game we looked like the team more likely to win the game," said O'Neill.
"Our performance was good - we come away thinking it's not a game we should have lost."
Xaver Schalger put Austria in front four minutes after half-time but Corry Evans' deflected effort eight minutes later drew the hosts level, before Lazaro's late intervention.
"To lose the game with the very last kick of the ball when we were in possession trying to win the game is hugely disappointing," added O'Neill, whose side had already been relegated from Group B3 before Sunday's match.
"They turned the ball over and it was a bit of individual quality that won it - a wonderful piece of skill and a great goal.
"They brought on a top player in [Marko] Arnautovic and he combined with Alaba to create the goal.
"I felt there were a lot of poor decisions by the referee. George Saville was dragged back by a player who was already on a yellow card but the ref let it go."
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'Players trying to do the right things'
The Northern Ireland manager believes a lack of regular first-team football has been a drawback for many of his players but refused to be downbeat about his side's Nations League campaign, despite the disappointing nature of the results.
"We tired a bit at the end, you could see that especially in the last six or seven minutes. That's partly down to players not playing regularly enough," said O'Neill.
"We have dropped into League C now and will probably miss out on a play-off opportunity but the level of performances has been good and the players are trying to do the right things.
"The results on balance have been extremely harsh on us but we have to forget about the Nations League now and take our good performances into the European qualifiers.
"We haven't got what we've deserved - we've created good chances but not taken them - but come March we'll be ready for the Euro qualifiers."
O'Neill has repeatedly emphasised that his side's recent matches have been about blooding young talent - giving them experience and building a squad capable of challenging for Euro 2020 qualification.
"We have been introducing new players to football at this level and the only way to do that is by getting them time on the pitch," he added.
"For many, these games have been their first exposure to this level and they've had to learn quickly.
"We are a young team and we're asking players to step up from Championship level and sometimes League One level. Sometimes they don't manage games particularly well so they need time."