World no. 55 Skachkov defeated no. 1 seed Liam Pitchford of Britain in the second stage men's final of the World Singles Qualification Tournament in Doha, Qatar.
Thanks to his unforgiving forehand, the Russian saw off the world no. 15 in just over 40' with a 4-1 win (11-7, 7-11, 11-8, 14-12, 11-7).
Pitchford will have one more chance to qualify for his third Games at the European Olympic Singles Qualification Tournament scheduled at the end of April (21-25) in Odivelas, Portugal.
In the women's stage two final, world no. 40 Sawettabut won 13-11, 5-11, 11-9, 11-9, 11-8 against Spain's Maria Xiao, seeded 13th.
“I feel very happy to have qualified for the Olympics. These will be my second Olympics," no. 3 seed Sawettabut told the ITTF after her win.
"It was very difficult, she is a left-hander and she played very well in this match. I tried my best, tried to calm down and play it point by point.”
Skachkov and Sawettabutt bounced back after they couldn't qualify during the first stage in Doha.
They join seven other players, who had previously qualified on day two and three of the qualifying tournament, which started on Sunday 14 March.
Britt Eerland of the Netherlands, Sweden's Linda Bergstrom, Russia's Polina Mikhailova and Monaco's Xiaoxin Yang were the winners of their respective knockout brackets in the women's competition on Monday 15 March.
On the following day Czech Republic's Lubomir Jancarik, Hungary's Bence Majoros and Slovakia's Yang Wang booked their tickets for Tokyo in the men's singles contests.