Ben Rattray, 27, and Andy Hill, 28, from Sydney, won the first World City Chase competition after a 33-hour dash around Chicago involving a 4am golf game, a parachute jump and a backyard makeover.
Described as "part urban obstacle course, part scavenger hunt", City Chase originated in Canada in 2004 and now includes heats in Sydney and London, as well as eight Canadian cities.
The Australian pair qualified for last weekend's international final after winning the inaugural Sydney event in March.
In Chicago they had to play golf, swim in freezing Lake Michigan, swing on a flying trapeze, jump from a plane at 14,000ft (4,267m) and canoe down a river for 22km.
They crossed the finish line in first place at 6.30pm local time on Saturday.
Mr Rattray said the pair were "completely floored" to have won the world title.
"We are both so proud to be bringing the first-ever City Chase world championship title to Australia and we're already geared up for an even bigger and better Australian series next year," Mr Hill said.