The world number four enjoyed a stunning season, finishing as runner-up at Roland Garros and Wimbledon, winning her second career title in Dubai and then triumphing with Italy in doubles at the Olympics and again in Malaga.
Sinner, who lost last year's final to Novak Djokovic, did not put a foot wrong this time round as he finished undefeated and without dropping a set to earn $4,881,500 in prize money.
Spanish superstar Rafael Nadal is aiming to cap his emotional farewell from tennis with another Davis Cup triumph in Malaga next week.
Fifth-ranked Fritz triumphed 6-3, 3-6, 7-6 (7/3) over world number two Zverev in a thrilling match at the season-ending event in Turin.
World number four Daniil Medvedev said the ATP Tour calendar needs to be refocused around the Grand Slams and Masters 1000 events with the lower-tier ATP 250 tournaments moved to an optional slot later in the year.
The small furry objects that are the focus of every tennis player's energy are spinning the stars at the ATP finals into a fury and leaving them deflated.
Czech Barbora Krejcikova on Sunday called for respect and professionalism in sports media as she hit out at "unprofessional" remarks made about her appearance during a broadcast on the Tennis Channel.
Nadal, the winner of 22 Grand Slam titles, announced last week that he will retire from tennis after the Davis Cup Finals in Malaga next month.
When a teenaged Rafa Nadal bounced in to Roland Garros in pirate pants and sleeveless shirt in May 2005 before scything through the draw, few realised it marked the start of an unprecedented era of sporting domination.
They started dating in 2020 but recently were rumoured to have split. "That's our personal life so you don't need to know that," said 29-year-old Siniakova.
Andy Murray's trophy-filled career came to an end at the Paris Olympics on Thursday as another chapter closed on tennis's golden generation.
World number three Carlos Alcaraz edged closer to an Olympic Games showdown against Novak Djokovic on Thursday with a storming display which brought the queen of Spain to her feet.
World number seven Zheng triumphed 6-2, 7-5 and will face either Croatia's Donna Vekic or Anna Karolina Schmiedlova of Slovakia in the gold medal match.
Matthew Ebden had not expected to last long against Novak Djokovic in the first round of the Olympics on Saturday and he was not wrong - but it left the Serbian wondering why the Australian doubles specialist was competing in the singles.
The 38-year-old effectively ruled himself out of the singles tournament as he battles a thigh injury picked up in training at Roland Garros, the scene of 14 of his 22 Grand Slam triumphs.
The Italian said he was "sad and disappointed" to drop out, adding that he had started feeling unwell on Monday after a practice week in Monaco.
The 37-year-old, a two-time Olympic champion, is planning to play in the singles and doubles at his fifth Games.
The 38-year-old Spanish left-hander has a protected ranking of ninth to put himself into the field for the Flushing Meadows fortnight, which begins on August 26.
"I don't have any limitations in my mind. I still want to keep going and play as long as I feel like I can play on this high level."