He has been around a while, turning professional back in 2002 without setting the world alight, but his persistent pursuit of his goals is finally starting to pay some dividends at the age of 31.
It is a study in dogged determination that could serve as an on-court parallel to the script of the blockbuster Rocky movies.
Klaasen was on the point of quitting the game two years ago. But like the fictional Rocky Balboa, he decided to keep on punching away at it.
Not that the whipcord doubles specialist would even begin to match even a fictional ring heavyweight – he would probably concede a 6-0, 6-0 disadvantage – but the will to succeed ran strong and he carried the flame in the satellite tours and skirted the fringes of the bigger tournaments.
Klaasen has not even been a household name in his own country and was virtually unknown outside the tennis fraternity when he was first named as a member of the South African Davis Cup squad.
But even though he has become something of a fixture in the colours of his country, playing Davis Cup outside the exalted atmosphere of the World Group is a far cry from the glamour of Wimbledon, Roland Garros and Flushing Meadows.
But now, from the very brink of obscurity, the man who moved to Cape Town with his tennis-playing parents as a teenager to allow him to get a more thorough background in the game, has the biggest chance of his career.
For even if Klaasen and his American partner Eric Butorac fall at the final hurdle in the Australian Open doubles today, reaching the Grand Slam final in Melbourne already represents a quantum leap in his career.
The immediate assignment for Klaasen and Butorac is to get the better of Pole Lukasz Kubot and his Swedish partner Robert Lindstedt. The duo can take great heart from having iced the legen-dary Bryan brothers, Bob and Mike, sensationally knocking the American winners of six Australian titles out in the third round.
Klaasen will never be a no-name brand player again… a win will write his signature up in lights.