New York, NY, USA, 1 September 2016 | Darren Walton/AAP

James Duckworth rued a poor serving display after his US Open campaign ended in a gallant four-set second-round loss to French star Jo-Wilfried Tsonga.

The Australian wildcard put up a stiff challenge before going down 6-4 3-6 6-3 6-4 to the ninth seed in stifling conditions at Flushing Meadows on Wednesday.

Duckworth landed just 50 per cent of first serves and was under constant pressure throughout, yet hung tough to save 21 of the 25 break points he faced.

But he eventually cracked, broken from 40-15 up serving at 4-4 in the fourth set as he tried valiantly to force a deciding fifth set.

“You never know, at least get to a tiebreaker and some times they’re a bit of a coin toss,” he said.

“I created opportunities. Wasn’t able to take a few of them.

“I feel like there were still quite a few things I could have done better but I still matched it for the most part with a top-10 player so I’ve got to take some confidence from that.”

Duckworth, whose ranking slumped to 195th after missing four months this year with wrist and elbow injuries, will climb to No.171 in the world after winning his maiden match at the US Open.

The 24-year-old will return home to Sydney, and possibly be used as a hitting partner for Australia’s Davis Cup playoff with Slovakia in two weeks, before heading to Asia for several tournaments.

“I’m pretty eager now to drop that ranking so I can get direct entry to these events again,” Duckworth said.

“I’m keen to just keep improving.”