In set two, the 21 year old Gauff took leads of 3-1 and then 5-3 following a mix of more aggressive baseline play and several Sabalenka errors.
Gauff hit three forehand returns long in the following game as Sabalenka held serve to reach 4-5.
The American struck several additional forehand errors in the following two games as Sabalenka led 6-5 after winning three games in a row.
Serving to stay in the set, Gauff regrouped after trailing 0-30 and facing a matchpoint to hold serve and enter a tiebreaker.
Sabalenka struck two powerful backhands to take a 3-0 tiebreaker lead.
Gauff leveled the tiebreaker at three points all.
Coco netted two crosscourt forehands to face a second matchpoint at 3-6 before doublefaulting to end the match after one hour and 39 minutes of play.
For Gauff it would be her 8th doublefault of the day as she was not able to control enough points and hit too many forehand errors to lose.
Sabalenka rose to a 31-5 win loss record for the year after posting the final round win.
In Sunday's men's final, the sixth ranked Jack Draper of Great Britain split the first two sets with Casper Ruud before taking a 1-0 final set lead.
However Ruud then struck many powerful forehands to take the lead at 5-3.
Draper hit three crosscourt forehand winners to hold serve to reach 5-4.
Serving for the match, Ruud struck two down the line forehand winners to set up matchpoint.
Ruud then struck a final powerful down the line forehand which Draper sent down the line long to end the match after two hours and 29 minutes of play.
As a result of their final round results, the 23 year old Draper moved from six to five in the rankings while the 26 year old Ruud moved from 15 to seven.