Nigeria coach Gernot Rohr admitted his players were relaxed at the end of the game when they wanted to force Algeria into an additional 30 minutes of football in Sunday's semi-final clash.
The Super Eagles fought back from a goal deficit in the second half to hold Djamel Belmadi's men to a 1-1 draw until injury time.
After four additional minutes in stoppage time, Riyad Mahrez rose to the occasion and scored a free-kick in the last minute of the game to break Nigerian hearts.
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The loss dashed the Super Eagles' hopes of claiming their fourth Afcon title but Rohr praised his team's fighting spirit despite the late stunner from 'football genius' Mahrez.