Three-time Grand Slam champion Andy Murray has kept his No. 1 ranking as the Scot leads the charge with 7,750 points at this week's updated ATP Rankings List. Murray, who surpassed Serb Novak Djokovic at the top past November, has completed his 39th week as the world No 1, according to ATP site. The Scot is on the verge of tying 1972 US Open champion Ilie Nastase at No. 14 for the total weeks at No. 1 ranking as the Romanian tennis legend spent 40 weeks at the top.

However, the real challenge lies ahead of Murray as Spain's Rafa Nadal remains a strong candidate to dethrone the 30-year-old by the end of August.

The gap between the two is a close one as the Spanish tennis player has 7,465 points collected on the board.

Meanwhile, Roger Federer didn't make any moves as he is still ranked just behind Murray and Nadal, while Djokovic has fallen to number five, ranked behind fourth Swiss Stan Wawrinka.

Nadal's decision to skip Hamburg played key part

Clay-court specialist Nadal was as sought as anyone by ATP Hamburg organizers but decided to skip last week's German Tennis Championships. The tournament was reportedly ready to pay a €500,000 fee entrance to the Spaniard, who went all the way at the clay of Hamburg twice; 2008 and 2015.

Argentine's Leonardo Mayer, the eventual winner of the German 500 class event, earned €323,145 for completing a winning run.

Had Nadal decided to come to Hamburg and ended winning it all, he would have surpassed Murray on this week's list. However, the 31-year-old remained committed to looking at the bigger picture as he is eyeing to finish the season on a high note. It would be hard for the world No. 2 to hit clay after the recently finished grass season and then head to the United States for the hard-court season.

As early as in Montreal

Two Olympics champions Murray and Nadal will remain inactive this week as they're preparing for the Rogers Cup, Montreal, August 7-13.

Murray won't be losing his position when the list gets updated next Monday but that could change in two weeks from today.

Murray, who is dealing with a hip injury, hasn't yet confirmed his presence at the Montreal Masters.

Should he skip the event, and Nadal reaches at least the semi-finals -- the Spaniard would replace the 30-year-old at number one.

Nadal, the former world No. 1, hasn't been ranked at the top in more than three years -- since July 2014. The 31-year-old has spent 141 weeks as the world No. 1 so far in his career.