Here is a timeline of Djokovic's decline since the last of his 12 Grand Slam titles.
A season that produced the biggest shake-up in men's tennis for more than a decade draws to a close next week with three ATP World Tour Finals debutants striving to sign off breakthrough years with a large exclamation mark.
Rafael Nadal is confident he will be ready to compete in this week's Miami Open despite turning his ankle in practice, the second seeded Spaniard said on Tuesday.
Joaquin "El Chapo" Guzman, world's most-wanted drug lord who fled through a tunnel from a maximum security prison in a made-for-Hollywood escape that deeply embarrassed the Mexican government and strained the country's ties with the United States six months ago, has been recaptured.
World number five Roger Federer delivered a tennis masterclass to beat rising star Alexander Zverev 6-1, 6-3 and clinch a record ninth Halle Open title on Sunday as he lay down a marker in the lead-up to Wimbledon.
Grigor Dimitrov reached his first grand slam quarter-final in over two years on Monday by defeating an injury-hampered Denis Istomin 2-6, 7-6(2), 6-2, 6-1 to end the Uzbek wildcard's fairytale run at the Australian Open.
After six months out of the game, Federer's fairytale return continued under the lights of Rod Laver Arena where he emphatically quashed doubts about his fitness in three hours and 24 minutes of high-octane tennis.
India's top singles player Somdev Devvarman was on Saturday drawn to a play a qualifier while wild cards Yuki Bhambri and Jeeven Nedunchehziyan will have to fight it out with top-100 players in their first rounds at the Aircel Chennai Open.
While Lyon rallied to hold Leipzig 2-2 after a Memphis Depay strike, it was the English clubs who made a mark on the night. Liverpool and Chelsea moved into the last 16 with contrasting wins and now all four English clubs, including Manchester City and Tottenham Hotspur, are in the Champions League knockouts this season.
Alexandre Lacazette's free-kick sent Arsenal into the Europa League semi-finals with a comfortable 1-0 win away over Napoli, while Chelsea beat Slavia Prague 4-3 in a roller-coaster game, helped by a Pedro brace.
Slowly but surely Andy Murray is scratching his name alongside the all-time grasscourt greats on Wimbledon's hallowed lawns.
Premier League leaders Arsenal showed their class as they comfortably beat north London rivals Tottenham Hotspur 2-0 to book a place in the FA Cup fourth round in an electric atmosphere at the Emirates Stadium on Saturday.
Former world number one Rafael Nadal displayed more signs of a return to top form with a ruthless 6-2, 6-1 hammering of Stanislas Wawrinka to reach the semi-finals of the Shanghai Masters on Friday.
Liverpool's UEFA Champions League challenge ended in a 1-1 draw against FC Basel, who booked their spot in the last 16.
Griezmann special earns Atletico 1-1 draw at Sevilla
Australian Bernard Tomic has hit back at Roger Federer's suggestion that he is a long way from being a top 10 player, saying the 17-times grand slam champion faced a quality deficit of his own compared to Novak Djokovic.
According to Twiplomacy, a study conducted by global public relations and communications firm Burson-Marsteller, United States Barack Obama is the most followed leader on the microblogging site, followed by Pope Francis, Narendra Modi, and Turkey President Recep Tayyip Erdogan and the White House.
The triple grand slam winner, who will take over from Serb Novak Djokovic at the top when the rankings are updated on Monday, still went out on centre court for a practice session in front of a bemused crowd.
Villarreal's Adrian Lopez produced a stinging sucker punch in stoppage time to leave Liverpool reeling and move the Spaniards closer to a maiden European final after their Europa League last four first leg clash finished 1-0 on Thursday.
World No 1 Novak Djokovic recovered from another slow start to beat Spain's David Ferrer.
Athletic Bilbao missed a chance to tighten their grip on Spain's fourth Champions League qualification place when they had to come from behind to rescue a 1-1 draw at 10-man Villarreal in La Liga on Monday.
A toothless and haggard Real Madrid slumped to a humiliating 10th Liga defeat of the season on Sunday as they lost 1-0 at struggling neighbours Rayo Vallecano.
Champions Barcelona reclaimed top spot in La Liga on Sunday by overcoming a dogged Villarreal side to win 2-0 at home with goals from stalwart defender Gerard Pique and youngster Carles Alena taking them above Sevilla.
David Zurutuza struck twice to help Real Sociedad seal a remarkable comeback and beat Real Madrid 4-2 in La Liga.
Check out some of the up-and-comers who could cause an upset at Wimbledon this year.
With three of the four Grand Slam titles and a record six Masters Series crowns scooped up in a year of domination, Novak Djokovic could be forgiven for using the ATP Tour Finals in London as a well-earned lap of honour.
Rafael Nadal weathered an early serving storm from Kevin Anderson before dismantling the South African giant with a 7-5, 6-1, 6-4 masterclass to reach the quarter-finals of the Australian Open on Sunday.
News of all that's transpired on and off the football field
Barcelona snapped a four-match winless run in La Liga with a 4-2 home victory over title rivals Sevilla on Saturday to reclaim top spot but the triumph was marred by talisman Lionel Messi fracturing his arm and being ruled out for three weeks.
Rafael Nadal looked something close to his old masterful self on clay again as he crushed Czech Tomas Berdych.
Swiss second seed Stan Wawrinka advanced into the semi-finals at the Rogers Cup with a comprehensive 6-1, 6-3 victory over big-serving South African Kevin Anderson at the Aviva Centre in Toronto on Friday.
Reigning champions Novak Djokovic and Serena Williams have been named top seeds for the Australian Open starting on Monday.
A near flawless Novak Djokovic crushed Marin Cilic 6-0, 6-3 to set up a blockbuster Monte Carlo Masters semi-final with claycourt king Rafa Nadal, who came through a testing workout by David Ferrer on Friday.
Serena Williams must navigate a heavily American quarter of the draw including sister Venus to complete a calendar sweep of the four Grand Slams, while two sensational quarter-finals loom on the men's side after Thursday's U.S. Open draw.
A summary of Wednesday's matches in the UEFA Champions League.
Juventus raced into a 2-0 halftime lead after Napoli goalkeeper Alex Meret was sent off in the 25th minute. The visitors then had Pjanic dismissed and Napoli's Jose Callejon pulled one back before Insigne let the Turin side off the hook.
A struggling and edgy Rafael Nadal crashed out of the Miami Open.
Two time Miami Open winner Victoria Azarenka crushed Serbia's Jelena Jankovic.
Ten-man Manchester City staged a dramatic comeback with late goals from Leroy Sane and Raheem Sterling securing them a 3-2 win at Schalke 04 in their Champions League Round of 16 first leg.
US Open champion Marin Cilic made a shock first-round exit from the Shanghai Masters on Monday after losing 7-5, 2-6, 7-6(2) to fellow Croatian Ivo Karlovic.
