The 33-year-old finished with one of his poorest performances as Scotland suffered their first Calcutta Cup defeat at Murrayfield since 2004 – his debut season in the Six Nations. He was consequently certain to be dropped for this Sunday's match against Wales in Cardiff and, having admitted to contemplating quitting after the World Cup, clearly knew that with a number of contenders now vying for the No.10 shirt, his days as an internationalist were over.
"I was thinking about it, but the first game of the Six Nations was against England, Jacko [Ruaridh Jackson] was injured and being able to play against England was huge for me as there was a sense of unfinished business," he said. "After the game, after talking it over with my family, my girlfriend and close friends, I've come to the decision that now is the right time to retire from the international game. There are some really talented guys coming through and although I'm sad to be finishing my international career I have some fantastic memories of playing for Scotland and what that has meant to me."
While the Australian-born stand-off has been on the receiving end of constant criticism in some quarters, partly levelled at his playing style but also at some unfortunate off-field antics, there have been some extraordinary highs as he has accrued 67 caps for Scotland, scoring 266 points, including a Scottish record 17 drop-goals.
Voted Scotland's players' player of the 2007 World Cup, his Test career looked over when Andy Robinson omitted him from his first squad as national coach. Yet Parks fought back, claiming three man-of-the-match awards during the 2010 Six Nations and steering Scotland to a first Test series win in Argentina.