The 20-year-old scored his second successive fifth placing in the under-23 elite cross-country world cup, backing up last weekend's effort at Mt Saint Anne (Canada) with a good ride at Windham, a ski resort in upstate New York.
The Cannondale Factory rider has moved to seventh in the world cup standings with a final round in two weeks before the world championships in Andorra next month.
Cooper was one of the fastest on the course over the final two laps, coming within 30 seconds of the podium.
Fellow New Zealanders Sam Gaze (Cambridge) and Craig Oliver (North Canterbury) were 14th and 45th respectively over the demanding course.
''The course was one big long climb and one fast descent with a lot of dust the whole way round,'' Cooper said.
''I felt a bit off at the start but battled hard to hold a solid position before finding my rhythm with around four laps remaining.
''I had a good crack at making the podium on the last couple of laps and overall I was happy enough on a course that doesn't suit my abilities.''
Kate Fluker, of Queenstown, had a challenging day, finishing 40th in the women's race, a lap down on winner Pauline Prevot (France).
Fluker has been in consistent form this year and lies 31st on the world cup standings.
Matt Walker (Rotorua) had a breakthrough performance in the downhill competition.
Walker, older brother of BMX rider Sarah Walker, finished 11th and was the leading New Zealander.
Sam Blenkinsop was the only other New Zealander in the top 20 as Brook MacDonald and George Brannigan both fell victim to the uncompromising Windham course.
Taranaki brothers Wyn and Ed Masters were 29th and 30th respectively.
Queenstown's Alanna Columb was the best of the women in 10th place, with Sophie Tyas 15th and Veronique Sandler 17th.
Downhill honours went to American Aaron Gwin and the incomparable Rachel Atherton (Great Britain).
The final round of the world cup for both cross-country and downhill is at Val di Sole, Italy, on August 22-23.
