During his appearance in the Diriyah Tennis Cup exhibition tournament in Saudi Arabia, the 25-year-old German defeated Austria's Dominic Thiem in two super tiebreaks.
World number 12 Zverev then lost to the Russian Daniil Medvedev, 6-4, 6-0.
Olympic champion Zverev left Court Philippe Chatrier at Roland-Garros in June in a wheelchair, subsequently undergoing surgery to repair torn ligaments in his right ankle.
He subsequently missed Wimbledon and the US Open.
A planned return at the Davis Cup in September came up short when Zverev pulled out after experiencing "extreme pain".