The pair, from the UK but currently living in Queenstown, crashed their Toyota Highlander near the Wye Creek Bridge on State Highway 6 between 3am and 5am.
Initial indications were that the driver lost control and failed to take a bend on the southern approach to the bridge, police said.
The vehicle crashed through a roadside barrier before plunging an estimated 30m into the Wye Creek ravine.
Both men were able to get out and the passenger scrambled up to the road and flagged down a passing motorist.
Emergency services attended and a paramedic was lowered from a Heliworks helicopter to winch the driver out of the ravine.
He was transferred to an ambulance and both men were taken to Lakes District Hospital.
Traffic was delayed briefly while the helicopter crew were at work.
The 24-year-old driver has leg and possible internal injuries, while his 22-year-old passenger sustained minor injuries.
Police say it is too early to say what caused the crash. However, it appears both men were wearing safety belts, which undoubtedly prevented further injuries.
Both men were ''extremely lucky'', police said.
