The 30-year-old Wasps flier scored his 13th try on his 61st appearance and then announced his intention to quit international rugby at the end of November's World Cup.
"I feel quite emotional knowing it's my last 6 Nations," he said.
"I hope to get to the World Cup and I'll probably call it a day after that.
"I will be 31 after the World Cup and I've done my bit for Scottish rugby. I'll play here again at some stage, hopefully in the build-up to the World Cup.
"But I decided at the start of the season I would give it one last shot.
"I've quite enjoyed the 6 Nations. I didn't enjoy getting beat but I've enjoyed being involved with the squad and seeing some progress being made."