Denis Kudla stopped Kei Nishikori‘s six-match winning streak on the ATP Challenger Tour Thursday, when the American survived the former World No. 4 at the Cranbrook Tennis Classic in Bloomfield Hills, Michigan.

The World No. 180 Kudla defeated Nishikori 6-3, 3-6, 6-3 to reach the quarter-finals at the Challenger 75 event, which was the Japanese star’s second tournament in 20 months. Nishikori began his comeback in June at the Caribbean Open in Puerto Rico, where he went on a dream title run with the loss of just one set.

Despite making 45 per cent of his first serves, Kudla turned the two-hour, 21-minute contest into a physical battle and played with depth from the baseline to hurt Nishikori, who let slip a break advantage at 2-1 in the decider. The 30-year-old Kudla will next meet Kazakh Mikhail Kukushkin in the last eight.

Nishikori will be in ATP Challenger Tour action again next week in Chicago, Illinois. The 12-time tour-level titlist will then play the ATP Tour events in Atlanta and Washington, D.C. The 33-year-old, who underwent arthroscopic left hip surgery last year, is No. 478 in the Pepperstone ATP Live Rankings.