Mark Martin took a moment to look back at a special day in his racing career. One that combined history, dominance, and legacy at one of motorsport's most iconic venues - the Indianapolis Motor Speedway.It was 27 years ago to the day - July 31, 1998 - when Mark Martin drove the bright orange No. 6 Pontiac Firebird to Victory Lane in the fourth and final round of that season’s International Race of Champions (IROC). The win, scored in front of a packed Indianapolis crowd, sealed his third straight IROC title and his fourth in five years.On July 31, the NASCAR Hall of Famer reposted an image of his 1998 IROC victory at IMS on X and wrote:"Living my dream."The IROC series, started in 1974 by Mike Phelps, Roger Penske, and Les Richter, was created as a way to pit the best drivers from different disciplines against one another in identically prepared cars. The races didn’t count toward any regular-season championships, but in many ways, they mattered just as much.Names like Mark Donohue, who won the inaugural title, and later Dale Earnhardt, Al Unser Jr., and Martin himself, all competed across the years. The 1998 edition was the twenty-second season of IROC and brought together top-tier drivers from NASCAR, IndyCar, and other racing disciplines.Mark Martin (55) leads the NASCAR Sprint Cup Series Samuel Deeds 400 At The Brickyard. Source: GettyMartin started dead last in the 1998 finale at IMS in a 12-car field that included Jeff Gordon, Terry Labonte, and Jeff Burton. It made the win even more dramatic. He remains the fifth time driver in IROC history to win from the back. And by the end of the day, he also took home the $225,000 purse.Mark Martin's IROC 1998 win at IMS capped off a championship seasonMark Martin before the 2011 NASCAR Sprint Cup Series FedEx 400. Source: GettyThe 1998 IROC field competed in identically prepared Pontiac Firebird Trans Am race cars, each finished in solid colors without sponsors, with only the driver’s name on the roof. The goal was to eliminate any equipment advantages, something that suited Mark Martin's methodical, no-nonsense driving style.By 1998, the cars used were specially prepped Pontiac Firebird Trans Ams - same engines, specs, and opportunities. That year's field featured 12 drivers and opened at Daytona International Speedway in February, where Jeff Gordon took the first win. Martin finished third that day.The next round was held at California Speedway, where Martin found his rhythm. He took the win in commanding fashion. In the third round at Michigan International Speedway, he finished second to Jeff Burton, who was Martin's closest title contender that year.It came down to the series finale at Indianapolis, making its first-ever appearance on the IROC calendar. The event also served as a prelude to the 1998 Brickyard 400 and added more prestige to the season-ending round.Martin's charge not only brought the crowd to its feet but sealed his third consecutive IROC title and his fourth in five years. He ended the year with 86 points, well ahead of Jeff Burton in second with 57. No other driver in IROC history had matched that level of consistency over such a short span.Martin would later go on to win a fifth IROC title in 2005, making him the most decorated IROC champion in the series' 30-year history.