By winning her first hard-court final since the 2017 US Open, she'll be No. 10 when she returns to New York. Keys entered the tournament on a streak of early flameouts in her past three tournaments and a tough draw for the week.
Back on the court to receive the trophy, she told the crowd: "If you told me this is where I would be a week ago, I would have laughed in your face!"
Yet there she was, moving up to the No. 10 ranking after a gritty showing that was typical of her week. She broke Kuznetsova to pull even in both sets at 5-5 and then pulled them out with a steady serve.
Keys hadn't made it past the second round in her last three tournaments, including Wimbledon. Now she has a good feeling with her favorite Grand Slam event at hand.
"It's definitely a great building block," Keys said. "I want to do well in New York and have a good end to the season."
At 34, Kuznetsova was the oldest finalist in the history of the Western & Southern Open. She beat three top-10 players in a tournament -- Sloane Stephens, Karolina Pliskova and Ashleigh Barty -- for the first time in her 19-year career.
The 153rd-ranked player got a late start on the season as she completed a seven-month recovery from a knee injury. In her ninth tournament of the season, she got her game together and got her best result in two years.
"Honestly, I didn't expect to be so good at this tournament," she said.
After what happened in Cincinnati during the week, nobody knows what to expect in the women's bracket in New York.
Serena Williams dropped out of Cincinnati because of back spasms that also forced her to withdraw from the final in Toronto. Naomi Osaka, the defending US Open champion, withdrew from her semifinal match Friday because of discomfort in her left knee that left her worried about her condition heading to New York.