In the 2005 IndyCar Series, Briscoe took pole position at Sears Point, but struggled on the ovals and was involved in several crashes.

His car climbed on top of the Cheever Racing entry driven by Alex Barron and went airborne into the catch fencing above the retaining wall and snapping in two.

He was released from hospital on 19 September and following some initial treatment in the US, moved to the specialist Formula Medicine facility in Viareggio, Italy, for the bulk of his rehabilitation.

During the winter, he tested with fellow Australian and Champ Car owner Kevin Kalkhoven's PKV Racing team.

In 2006, Briscoe was announced as an endurance driver for Holden Racing Team in the Australian V8 Supercars touring car series.

Briscoe signed a deal to drive for Penske Racing's Porsche RS Spyder LMP2 car in the American Le Mans Series.

He scored his only class victory that year at Petit Le Mans, winning with fellow IndyCar driver Hélio Castroneves.

[4] Briscoe earned his first career win at the Milwaukee Mile just one week after Indy, holding off Scott Dixon and avoiding a late crash involving Marco Andretti, Ed Carpenter, and Vítor Meira.

Briscoe became the sixth driver in IndyCar history to score his first win while driving for Penske, following Mark Donohue (in 1971), Tom Sneva (1975), Rick Mears (1978), Paul Tracy (1993), and teammate Hélio Castroneves (2000).

Briscoe also became the first Australian to claim victory at their home event, the 2008 Nikon Indy 300, on 26 October 2008, after countryman and favourite Will Power crashed out early in the race.

Later, just before the Toyota Grand Prix of Long Beach in April, Level 5 announced it had signed Briscoe on as a full-season P2 driver with Tucker, going on to win six times across the season.

Meanwhile, just before the 2013 Grand Prix of Alabama in April, Chip Ganassi Racing announced they had signed Briscoe to return to the team for the 2013 Indianapolis 500 as a 3rd entry.

The final race of this campaign, also at the Gold Coast 600, saw Briscoe take his first championship podium driving with Russell Ingall.

For the 2015 IndyCar Series season Briscoe had been in negotiations to race for Schmidt Peterson Motorsports, but that fell through when financial arrangements could not be made for the team to field a third car.

Meanwhile, Briscoe continued a relationship with Corvette Racing in the GTLM category that had commenced in 2014 with selected entries as a third driver in the endurance United SportsCar Championship (IMSA) events.

Briscoe was selected to join the IMSA team which, alongside former IndyCar rival Scott Dixon and Richard Westbrook, also made annual appearances in the WEC's 24 Hours of Le Mans.

[13] Briscoe switched to the Prototype class for the 2020 IMSA WeatherTech Championship, partnering with Renger van der Zande as full-time driver at Wayne Taylor Racing.

[14] In October 2020, Briscoe, van der Zande and Dixon won the 2020 Petit Le Mans at Road Atlanta.

He attended Trinity Grammar School in Summer Hill, Sydney, Australia, however he had left to compete in Europe before completing his education.