John Millman has set aside his Davis Cup disappointment to reach the last 16 of the Open Sud de France in Montpellier.
The 28-year-old Queenslander caused a major upset when he eliminated No.8 seed Yuichi Sugita in three sets.
After losing the first set 7-5, Millman took the next two sets 6-3 and 6-4.
The win ended a disappointing period for the world No.109, who was omitted for rising star Alex de Minaur (world No.139) in Australia's Davis Cup team which lost to Germany last week.
Millman's win sets up a clash with Frenchman Benoit Paire and a possible quarter-final match-up with No.2 seed Lucas Pouille.
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Meanwhile, top-seeded David Goffin of Belgium reached the quarter-finals beating French veteran Gilles Simon 6-4 6-2.
The 33-year-old Simon had won two of their three previous matches but dropped his serve six times.
Sixth-seeded Russian Andrey Rublev joined Goffin in the last eight with a 6-2 6-1 win against Frenchman Jeremy Chardy.
In remaining first-round play, fifth-seeded Richard Gasquet of France swept aside Daniil Medvedev of Russia 6-0 6-3.
Gasquet did not face a break point and next plays Pierre-Hugues Herbert, who won 7-6 (7-4) 6-7 (7-5) 6-4 against Kenny De Schepper in an all-French match.
Ruben Bemelmans of Belgium took only 50 minutes to beat French wild-card entry Calvin Hemery 6-1 6-2.