The Serb easily beat the Spaniard 6-3, 6-4 at the O2 Arena.
World No. 1 Novak Djokovic remained at the top of the rankings chart
Swede Robin Soderling claimed his second major upset at the ATP World Tour Finals on Wednesday when he beat world number three Novak Djokovic 7-6, 6-1.
Spain hope new world number one Carlos Alcaraz will be ready for their Davis Cup tie
The Indo-Pakistan duo will take on third seeds Jarkko Nieminen of Finland and Robert Lindstedt in the championship round.
Rafa Nadal was eliminated from the ATP World Tour Finals, on Thursday, after being outgunned by an inspired Jo-Wilfried Tsonga in an absorbing late-night battle at the O2 Arena, in London.
German fourth seed Alexander Zverev beat Spaniard Pablo Carreno Busta 7-6(4) 6-2 on Friday to set up a Miami Open final showdown against big-serving American John Isner, who earlier overwhelmed Juan Martin del Potro.
The Indian duo of Mahesh Bhupathi and Rohan Bopanna has set up a summit clash with Leander Paes and his Czech partner Radek Stepanek after both the pairs won their respective semi-final matches in the Shanghai Masters on Saturday.
Rohan Bopanna and Andre Begemann suffered a quarter-final exit from the ATP Citi Open after a close defeat against Treat Huey and Dominic Inglot in Washington.
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.
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.
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.
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.
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.
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.
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.
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.
Having Lendl, as I said, can only serve him as an incentive for an improvement, says Djokovic
Novak Djokovic cruised through his first singles match in Australia since being deported last year.
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.
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.
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.
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.
Tsitsipas pulled out of the Wimbledon warm-up event in Halle, Germany, because of personal reasons
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.
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.
The German picked up two ATP titles in Cologne and also made the final of the ATP Masters 1000 event in Paris in an encouraging close to the season.
Both breezed through their semi-final on Saturday.
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.
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.
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.