By Martyn Herman
LONDON (Reuters) - New world number one Andy Murray was born a week before Novak Djokovic and won the pair's first junior tussle on the tennis court.
Since then he has spent his professional career playing catch-up with the Serb who always found a way of staying one step ahead.
On Saturday, in the same City of Light where five months earlier he was powerless to prevent Djokovic completing a career grand slam by winning their French Open final, the Scot finally caught up with his elusive rival.
His semi-final walkover -- after Canadian Milos Raonic pulled out of their Paris Masters semi-final with a leg injury -- means Murray has risen to number one in the world for the first time in his career, ending Djokovic's seemingly unshakeable 122-week grip.
Murray, 29, is the oldest first-time ATP number one since John Newcombe briefly scaled the summit in 1974 and is the 26th player to reach the top since rankings were introduced.
Djokovic, of course, got there first in 2011.
The Serb also boasted five grand slam titles when Murray claimed his first at the 2012 U.S. Open.
And when the Scot led Britain to their first Davis Cup crown in more than 70 years in 2015 it was five years after Djokovic had done the same for his country.
Murray owns two Olympic gold medals to Djokovic's zero but when it comes to evaluating tennis greatness, the number one ranking is a pre-requisite.
That Murray achieved it during a golden era for men's tennis graced by Roger Federer, Rafael Nadal and Djokovic exonerates him entirely for taking so long.
Since 2004, a year before Murray turned professional, only that trio have topped the rankings. The Scot got to number two in 2009 but has banged his head on a glass ceiling since.
"Three guys in a 13-year stretch, that's unprecedented," Murray's former coach Brad Gilbert told Reuters.
"Challenging for number one means you ... can't have a bad week or few weeks. That's why Federer, Djokovic and Nadal have sustained it so long.
"It's taken Murray a long time. Three years ago it was just a hope for Andy but this year it's been a belief," said the American.
Seventeen-times grand slam champion Federer holds the record of 302 weeks spent at number one while 14-times major winner Nadal has enjoyed 141 weeks on top of the pile.
Djokovic, who has 12 slams after beating Murray in the Australian and French Open finals this year, is fifth on the all-time list with 223 weeks.
Murray, for so long the "other man" in the so-called Big Four, is unlikely to get close to those totals although for sheer stickability he is their equal.
He could have been eaten up by an inferiority complex but Murray has stuck to his task.
With the advancing years catching up on Nadal and Federer, Murray has hunted down Djokovic relentlessly.
He trailed Djokovic by a massive 8,035 points after that sizzling June day in Paris when the Serb not only won the French Open final but also seemed to be turning men's tennis into his own personal fiefdom.
Number one looked like mission impossible for Murray but some cracks appeared in the Djokovic facade when he fell early at Wimbledon.
The Scot went on to defeat Raonic in the final, saying later that he and coach Ivan Lendl had been plotting a course to the top spot.
While Djokovic's form since the French Open has fallen away, Murray's run since Roland Garros has been epic.
He was undefeated on grass, winning at Queen's Club and Wimbledon and he scooped Rio de Janeiro gold during a 22-match unbeaten sequence that was ended by Marin Cilic in the Southern and Western Open final in Cincinnati in August.
Exhaustion caught up with Murray at the U.S. Open where Kei Nishikori knocked him out in the quarter-finals but he recharged and stormed back to claim titles in Beijing, Shanghai and Vienna.
His win over Raonic on Saturday was his 18th in a row, taking his tally for the year to a career record 73.
Murray will receive a hero's welcome at the ATP World Tour Finals in London later this month but the battle goes on with the year-end number one ranking still on the line.
"Lots of guys that have touched number one never finished the year number one," said Gilbert. "He wants that badly."
(Editing by Tony Jimenez)