The defender played a huge part in Scotland's 3-0 victory over Lithuania last night as they took another three crucial points in the race for a World Cup place.
Robertson scored the second with a brilliant strike from the edge of the box - his second international goal from 16 caps.
“It's a rare occasion and luckily it just flew into the back of the net," he told BBC Scotland.
"It'll be one that I'll always remember. Scoring for your country is always a massive honour."