Bouzkova dropshot to strike a down the line forehand winner to break serve and level the match at one set all.
Sitting in her chair on the following changeover, Williams could be heard saying the playing conditions for the day were “so windy” as the American provided her own commentary regarding her struggles of the day.
At one game all in the decisive third set, Williams held serve in what became the longest game of the match, a seven minutes long, four deuce game to lead 2-1.
Bouzkova continued to run down many balls but it was not enough as Williams delivered several powerful groundstroke winners to go ahead 4-1.
Williams remained ahead 5-3 following three consecutive holds of serve.
Serving for the match, the American struck an ace down the tee before hitting a second ace out wide, her 11th ace of the day at 115 miles per hour to lead 30-0.
Then at 30 all, Williams crosscourt backhand passing shot winner set up matchpoint which the American converted with a crosscourt forehand winner, her 36th winner of the day.
In tomorrow’s Toronto final, Williams meets the local favorite and unseeded Bianca Andreescu of Canada at 10:30am PST USA.
Williams has never faced the 19 year old Andreescu before.
The Canadian is best known for interesting mix of slice and power and for her performance in March at Indian Wells, California where she defeated Angelique Kerber of Germany in the championship match to win the singles title.
The winner of the Rogers Cup, a US Open Series tournament will receive 900 WTA Tour ranking points.
The US Open, the last of tennis’ four grand slams, will take place August 26th through September 8th in New York.
Serena Williams won her first of 23 grand slam singles titles as a 17 year old at the 1999 US Open.