Cape Town - Evergreen, 37-year-old Raven Klaasen is no respecter of age as he is demonstrating again by becoming the first South African to reach the elite, eight-pair ATP Finals for the fourth year in a row in London..
The amiable doubles specialist opened his current campaign along with New Zealand partner Michael Venus on Sunday with a workmanlike 6-3, 6-4 round-robin win against Rajeev Ram and Joe Salisbury - two former partners incidentally - as he attempts to earn a first ATP Finals crown and other landmarks that appear tantalisingly within his grasp.
It was with Ram in 2016 that Klaasen recorded his best ATP Finals performance by reaching the final, partnering the American again in the tournament in 2017, before switching to Venus for a further appearance last year and again this time around.
A continuing successful run into the knock-out stages in London could result in the Cape-born Klaasen improving or equalling his career-best world ranking of ninth from his present 11th position, although a tricky second match awaits the South African-New Zealand duo against second-seeded Lukasz Kubot of Poland and Brazil's Marcelo Melo.
But already Klaasen is a tennis phenomenon of sorts, breaking into the world's top 100 doubles players only after the age of 30 and winning his first ATP World tour title a year later.
It was the calculated decision by Klaasen to concentrate solely on doubles in the wake of a singles record that earned him nothing higher than a 208th world rating that turned his career around dramatically, if somewhat belatedly while making use of instinctive stroke-making in tight situations, unwavering dedication and speed around the court that have helped him reach Wimbledon and Australian Open Grand Slam finals, 16 ATP World Tour titles and career prize money closing in on R50 million.
And through it all he has remained steadfastly loyal to South African tennis while invariably making himself for Davis Cup and other commitments and building up a formidable record in team events - with a further key appearance expected in the inaugural ATP World Team Cup in Australia in January.