1989 Thriftway ATP Championship

The 1989 Thriftway ATP Championship, also known as the Cincinnati Open, was a men's tennis tournament played on outdoor hard courts at the Lindner Family Tennis Center in Mason, Ohio in the United States that was part of the 1989 Nabisco Grand Prix. The tournament was held from August 14 through August 20, 1989. Fifth-seeded Brad Gilbert won the singles title.

1989 Thriftway ATP Championship
Date	August 14–20
Edition	88th
Category	Grand Prix circuit
Draw	64S / 32D
Prize money	$485,000
Surface	Hard / outdoor
Location	Mason, Ohio, U.S.
Venue	Lindner Family Tennis Center
Champions
Singles
Brad Gilbert[1]
Doubles
Ken Flach / Robert Seguso[2]

Finals

Singles

Main article: 1989 Cincinnati Open – Singles

Brad Gilbert defeated Stefan Edberg 6–4, 2–6, 7–6

• It was Gilbert's 4th title of the year and the 18th of his career.

Doubles

Main article: 1989 Cincinnati Open – Doubles

Ken Flach / Robert Seguso defeated Pieter Aldrich / Danie Visser 6–4, 6–4

• It was Flach's 2nd title of the year and the 26th of his career. It was Seguso's 2nd title of the year and the 26th of his career.