#4 Juan Pablo Montoya - 2000 & 2015
Before stepping into F1 for 6 years between 2001 and 2006 with Williams and McLaren, Juan Pablo Montoya made his name in Indycar by winning the 2000 Indy 500. Racing for Chip Ganassi Racing, Montoya took a dominating victory in 2000 after leading 167 laps.
His only win of the season, it couldn't have come anywhere better, and after this, he made his way to Williams for his first F1 season in 2001. After a storied F1 career including 7 wins, 30 podiums and two 3rd place finishes in the World Driver's Championship, Montoya made his way to NASCAR and then back to Indycar in 2014.
Having the longest gap between two wins in Indycar racing, Montoya took victory again in 2015. Unlike his 2000 win, in 2015 Montoya had to fight for it against the likes of Scott Dixon, Will Power and other Indycar mainstays.
Nonetheless the Colombian took his second Indy win and etched his name in the history books.