Daria Kasatkina dug deep to fend off Daria Saville in the Granby Championships final and land the sixth WTA singles title of her career.
World number 10 Kasatkina took a 6-4 6-4 victory in one hour and 53 minutes of hard battle with her great friend, Saville showing resilience despite struggling with an ankle problem.
The outcome made Kasatkina the second Russian winner of the day on the WTA Tour after Liudmila Samsonova took the Tennis In The Land title in Cleveland, Ohio.
Kasatkina, who also won the Silicon Valley Classic in early August, will turn her focus away from a successful week in Canada and towards the US Open, which gets under way in New York on Monday.
The 25-year-old will be targeting a deep run at Flushing Meadows after achieving her best grand slam result in June when she reached the French Open semi-finals, before being prevented from playing Wimbledon due to a blanket ban on players from Russia and Belarus imposed by the All England Club.
In the second set of a gruelling and gripping tussle, Saville looked nailed on to come from 4-1 down to level at 4-4 when she led 40-0 in the eighth game, only for her game to briefly disintegrate, allowing Kasatkina to move 5-3 ahead.
Still, it was an unsteady Kasatkina at the other end of the court, and the Barcelona-based player was broken by Saville when serving for the match.
There was nothing secure about Saville on serve either, and Kasatkina had two match points in the next game at 15-40. She was unable to take either, or the third and fourth that arrived soon after. On her fifth opportunity, Kasatkina was relieved to see Saville hit wide.
Kasatkina begins her US Open campaign against British qualifier Harriet Dart on Monday, while Saville starts on the same day against Romanian Elena-Gabriela Ruse.