The Pole came into this week in seventh place, but with not much breathing room since only eight players qualify for the BNP Paribas WTA Finals Singapore presented by SC Global.
Radwanska's triumph moved her all the way up to third place, giving her a great chance to eventually qualify.
And though she still has a long way to go to threaten for a spot in Singapore, Venus Williams put herself back into the discussion by climbing three spots to 18th place after going all the way to the final of the Rogers Cup.
The Top 8 on the leaderboard are Maria Sharapova, Simona Halep, Radwanska, Serena Williams, Li Na, Eugenie Bouchard, Petra Kvitova and Ana Ivanovic. The only one of those not in action this week in Cincinnati is Li, who is suffering from a knee injury.
The biggest newsmakers on the doubles leaderboard were Montréal runners-up Cara Black and Sania Mirza going up a spot to third. Eight teams will qualify for Singapore, and Montréal champions Sara Errani and Roberta Vinci are the only duo to already clinch a spot.
Click here for the full Road To Singapore singles leaderboard and here for the doubles leaderboard.