Spain's Fernando Verdasco and David Marrero, the sixth seeds, upset the favourites 7-5, 6-7(3), 10-7 as the title went to a Spanish pair for the second successive year following the triumph of Marcel Granollers and Mark Lopez 12 months ago.
Crowd favourite John Isner advanced to his second career ATP Tour final on Friday with an 6-2, 7-6 victory over Spanish eighth seed Albert Montanes.
Frances Tiafoe is the first American man to make a US Open semi-final since Andy Roddick in 2006.
Top seeds Leander Paes and Lukas Dlouhy on Friday earned a shot at the title of the season opener ATP Brisbane International event after overcoming a second set lapse against Jurgen Melzer and Philipp Petzschner in Brisbane.
A doubles title continued to elude Mahesh Bhupathi and Max Mirnyi as they lost the Valencia Open final to British brothers Andy and Jamie Murray in Valencia.
Having Lendl, as I said, can only serve him as an incentive for an improvement, says Djokovic
The world number one swept aside Spain's David Ferrer in the Nasdaq-100 Open semi-final and set up a clash with Ivan Ljubicic.
Nikolay Davydenko ended seven years of pain against Roger Federer on Saturday, beating the world number one 6-2, 4-6, 7-5 to reach the final of the ATP World Tour Finals for a second successive year.
Mahesh Bhupathi and Mark Knowles enhanced their semi-final chances at the ATP World Tour finals after edging past Mariusz Fyrstenberg and Marcin Matkowski in a tough group B encounter in London on Tuesday.
Juan Martin del Potro took advantage of an error-strewn Marin Cilic performance to beat the defending champion for a seventh time in a row on Saturday to set up another Swiss Indoors final showdown with Roger Federer.
The fourth seeded Indo-Bahamas pair got a walkover from the American duo of Mardy Fish and Andy Roddick in the second round of the ATP Rogers Masters.
Top seed Andy Murray battled past Fernando Verdasco in the semi-finals of the Valencia Open on Saturday, beating the fourth-seeded Spaniard 6-3, 2-6, 6-3 to set up a final against Mikhail Youzhny.
Djokovic said the Spaniard remains his biggest rival.
Novak Djokovic ran into a spot of bother before seeing off Davis Cup team mate Viktor Troicki 4-6, 6-3, 6-1 to secure his place in the quarter-finals of the Paris Masters on Thursday. Czech Tomas Berdych booked his place for the ATP World Tour Finals with a 7-5, 6-4 win over Serb Janko Tipsarevic.
World number four Stan Wawrinka began the new season with a straight-sets victory over Viktor Troicki in his Brisbane International debut on Wednesday. Second seed Wawrinka edged out Troicki 7-6(5) 6-4 to maintain his perfect record against the Serbian whose seventh attempt at beating the Swiss failed at the Pat Rafter Arena. "I'm quite happy with my level at the start the year," Wawrinka said.
Nikolay Davydenko proved his victory over Roger Federer last year was no fluke by beating the world number one 6-4, 6-4 on Friday to reach the Qatar Open final. The Russian third seed, who beat the Swiss for the first time in the semi-finals of the ATP World Tour Finals in November, repeated the feat to progress to Saturday's final where he will face world number two Rafael Nadal.
Leander Paes and Radek Stepanek downed Jonathan Erlich and Richard Gasquet in straight sets to reach the quarter-finals of the ATP Indian Wells Masters tournament.
Novak Djokovic fought back from a set down to beat Andy Murray 4-6, 6-3, 7-5 at the ATP World Tour Finals on Wednesday and all but seal a place in the last four of the season-ending tournament.
A round-up of all tennis action on Friday.
Somdev Devvarman failed to make the main draw of the ATP BMW Open after losing to Alexandre Sidorenko in the third and final round of the qualifying event in Munich, Germany, on Monday. The second seeded Indian went down 1-6, 2-6 to his French opponent in an hour and six minutes.
Indian ace Leander Paes and his partner Lukas Dlouhy suffered a straight-set defeat against American Byran brothers Bob and Mike to be out of contention for a semi-final spot in the ATP World Tour Finals in London.
Rohan Bopanna and Aisam-ul-haq Qureshi crashed out of the ATP World Tour Finals after suffering their third consecutive defeat in the event, going down to the Polish duo of Mariusz Fyrstenberg and Marcin Matkowski in their Group B match, in London, on Thursday.
Holder Roger Federer produced an hour of sublime quality to crush Rafa Nadal 6-3, 6-0 at the ATP World Tour Finals on Tuesday and clinch a place in the last four with a match to spare.
Kyrgios added that he had been in communication with Tennis Australia chief executive Craig Tiley and United Cup tournament director Stephen Farrow about his injury.
Third seeds Leander Paes and Radek Stepanek qualified for the semi-finals of the ATP World Tour Finals after winning their second Group A match on Thursday. The Indo-Czech pair beat sixth seeds Marcel Granollers and Marc Lopez of Spain 7-5, 6-4 in 92 minutes.
Both breezed through their semi-final on Saturday.
Roger Federer sent a timely reminder to Rafael Nadal on Sunday, out-gunning the World No 1 to win the ATP World Tour Finals with an irresistible display of attacking tennis.
Rafael Nadal continued his resurgence with a thrilling 2-6, 6-4, 6-2 victory over world number two Andy Murray on Saturday to reach the final of the Monte Carlo Masters.
Andy Murray overcame second seed Guillermo Canas of Argentina 7-6, 6-4 to reach the Metz Open final.
Rafael Nadal, working his way back to top form after wrist problems last year, screamed with delight on reaching the Argentine Open semi-finals with a 6-1 6-1 rout of Federico Delbonis on Friday.
Spaniards Rafael Nadal and Garbine Muguruza were named as the International Tennis Federation (ITF) world champions on Friday - the first time in 19 years the awards have gone to players from the same country.
Belarusian ninth seed Aryna Sabalenka held off a spirited challenge from American Alison Riske to win 6-3, 3-6, 6-1 and successfully defend her Wuhan Open title on Saturday.
Bopanna had won this event with compatriot Divij Sharan in 2019.
Novak Djokovic turned on the style to outclass old adversary Rafael Nadal and reach the final of the ATP World Tour Finals with a 6-3, 6-3 victory at the 02 Arena in London, on Saturday.
The Indo-Pak Express knocked out Algerian Ouahab and Spaniard Vicente 6-3 6-4 in the semifinals.