World No 1 Novak Djokovic swept aside opponent David Ferrer of Spain in straight sets to set up China Open summit clash against third-seed Rafael Nadal.
Roger Federer called for a merger between the two governing bodies last month, with both Simon and ATP Tour Chairman Andrea Gaudenzi welcoming the suggestion. But some top WTA players have said they want an equal standing for the women players in a combined body.
Images from the men's singles Round of 16 matches at the US Open on Monday.
Alexander Zverev booked his place in the last four of the ATP Finals where he will face world number one Novak Djokovic after a 6-2, 6-4 win over Hubert Hurkacz in Turin on Thursday.
The winners of the Serbia-Germany tie will join Spain, Russia and Italy in the semi-finals.
Novak Djokovic proved to be a calming influence throughout
Novak Djokovic will be favourite to reach his 27th Grand Slam final when he faces Stefanos Tsitsipas in the French Open semis on Friday but what had been a smooth path through the draw has suddenly got a little rocky.
Italy sealed a place in the semi-finals of the ATP Cup by winning both singles matches against France
Frenchman Lucas Pouille claimed his first ATP title by beating Austrian top seed Dominic Thiem 7-6(5), 6-2 in the Moselle Open final in Metz on Sunday.
Factbox on Daniil Medvedev, who defeated world number one Novak Djokovic 6-4, 6-4, 6-4 in the US Open final on Sunday to win his first Grand Slam title.
Friday's match was a straight shootout for a last-four place, with world number five Rublev the favourite having won his four previous matches against Ruud.
Photos from the ATP World Tour Finals matches played in London on Tuesday.
Mahesh Bhupathi and Mark Knowles won the euro 891,000 ATP Swiss Indoor tournament in Basel on Sunday beating Christopher Kas and Philipp Kohlschreiber of Germany.
Now both men have made history for their country, leaving a permanent mark on the history books.
'The romanticism of late night tennis in New York, it's time to move past that'
A mouthwatering finale to the season ended before it even began on Sunday when Roger Federer was forced to pull out prior to the ATP World Tour Final showdown with Novak Djokovic.
But for the first time, that golden trio will be having an anxious glance over their shoulders. The past week in London has revealed a new fearlessness in the generation of 20 somethings expected to fill the void when they call it a day.
Laslo Djere won his first ATP title at the Rio Open on Sunday and then captured the hearts of the Brazilian crowd with a victory speech dedicated to his parents, both of whom died from cancer.
India's Sumit Nagal becomes 1st Indian to win match at Masters on clay since 1990!
Top seed Carlos Alcaraz snapped Daniil Medvedev's 19-match win streak with a 6-3, 6-2 rout in the Indian Wells final on Sunday.
Nadal, 31, pulled out of the Paris Masters before his quarter-final match last week after experiencing discomfort in his right knee during his third-round win over Pablo Cuevas.
Australian bad boy Bernard Tomic has shrugged off his Miami arrest and banishment from the Davis Cup team to successfully defend his ATP title in Bogota.
ATP, WTA cancel China events, including Shenzen Finals
Sumit Nagal had to be content with a runner-up finish at the ATP Tulln Challenger event after losing the singles title clash in straight sets to Czech Republic's Vit Kopriva, in Tulln on Sunday.
A very different Australian Open comes to a familiar end on Sunday as Novak Djokovic looks to thwart another challenge to his Melbourne Park dynasty from the latest Grand Slam aspirant in Daniil Medvedev.
Roberto Bautista Agut predicted a great future for Jannik Sinner after going down to the Italian teenager
Federer dismisses Nadal's suggestion to play ATP Finals on clay
World number one Carlos Alcaraz will not play in the Australian Open after picking up a right leg muscle injury during pre-season training, the Spaniard said on Friday.
Sania, the country's finest woman doubles player, who began the year with the number one ranking, closed it at number 9.
Reaching ATP Finals like winning a tournament, says Zverev
Stefanos Tsitsipas won 6-3, 6-3, 4-6, 4-6, 6-3 to book his place in the French Open final on Friday.
Serbian tennis ace Novak Djokovic has continued his domination on an unchanged top 10 in the latest men's tennis rankings issued by the ATP on Monday.
The 38-year-old, who has lost six games so far in the tournament, dispatched his hapless opponent in only 62 minutes winning the second-round match 6-0, 6-3.
Rafael Nadal's announcement on Friday that he will miss the ATP World Tour Finals because of appendicitis ended a difficult year for the Spaniard during which he has endured injury, illness and worrying defeats.
For the second time in three days at the ATP Finals, Rafael Nadal fought off one of the game's rising powers but beating Greek Stefanos Tsitsipas proved in vain as his semi-final hopes vanished on Friday.
Factbox on Austria's Dominic Thiem, who beat German Alexander Zverev 2-6, 4-6, 6-4, 6-3, 7-6(6) to win the US Open title on Sunday.
Factbox on Carlos Alcaraz, who beat seven-time champion Novak Djokovic
Rafael Nadal beat new world number one Daniil Medvedev 6-3, 6-3 in a rematch of their Australian Open clash to storm into the final of the ATP 500 event in Acapulco on Friday.
Second seed and world number 14 Roberto Bautista Agut outclassed Benoit Paire in a lop-sided semi-final to set up the singles title clash of the ATP Chennai Open with young Daniil Medvedev, who rallied to reach his maiden ATP final, in Chennai on Saturday.
Roger Federer added yet another record to his vast collection when he guaranteed becoming the oldest ATP world number one by beating Dutchman Robin Haase 4-6, 6-1, 6-1 to reach the semi-finals in Rotterdam on Friday.