That let rival Scott Dixon in to snatch the win and the lead of the championship in dramatic style.
Franchitti clung on to take third after strong support from team mate Tony Kanaan in the dying stages.
Franchitti easily kept the lead from pole position at very poorly formed start. Kanaan was ahead of team mate Danica Patrick even before the start line and Kanaan made way for her halfway around the opening lap.
Marco Andretti made a lunge at Ryan Hunter-Reay on the opening tour and the two clashed. Andretti fell behind Wheldon and after a couple of laps damage to Hunter-Reay’s front wing caused him to tumble down the order and retire.
There was little change of order in the opening laps with Franchitti pulling out a 1.6s advantage over Patrick. She had Kanaan, Helio Castroneves, Dixon and Sam Hornish queued up behind her before a four second gap to Dan Wheldon.
The first round of pit stops saw Patrick slip from second to sixth as she made a tentative return to the track on cold rubber. She moved up to fifth when Hornish spun at turn seven on lap 26.
Hornish was quickly caught by Wheldon and made an early pit stop on lap 37, followed by team mate Castroneves two laps later. But there was more drama for Patrick when Scott Sharp flew past her, bouncing over the kerbs at turn seven on lap 45. Sharp spun and Patrick took the long way around his car.
Dixon pitted on lap 47 and came out narrowly ahead of Kanaan. The Brazilian squeezed through but his compatriot Castronevces found himself hung out to dry by Dixon at the turn seven hairpin, the two briefly touching wheels.
The next round of pit stops brought Dixon even closer to the lead. He came out of the pits in front of Franchitti and Kanaan, but although Franchitti was able to scramble by Dixon boxed Kanaan in and took over second place.
With the drivers set to run the the flag the order looked settled. But a catastrophic error by Marco Andretti and Team Andretti Green very nearly took Franchitti out of the race – and handed the win and lead in the championship to Dixon.
Andretti had just exited the pits on lap 68 when Franchitti tried to sweep past him at the first turn. But Andretti turned in and the two made contact. Andretti was dumped into the tyre wall and Franchitti kept going – but with substantial damage to his front left wing.
The safety car stayed out for a couple of laps but once the race resumed Franchitti was powerless to keep Dixon behind and the New Zealander took the lead on lap 72.
Kanaan slithered around behind Franchitti trying to protect his team mate but Castroneves swept past the pair of them into second.
Respite from the onslaught came when AJ Foyt IV and Scott Sharp collided on lap 73, bringing out the safety car once again. This time Kanaan’s defence was perfect – holding back a train comprising Hornish, Patrick, Wheldon and pretty much the rest of the field as Franchitti was over 2s per lap slower than the leaders.
Castroneves made a few optimistic dives at Dixon in the closing stages but the Target Chip Ganassi driver resisted to take the win and move into the lead of the drivers’ championship.
Franchitti in third owed a gigantic debt to team mate Kanaan – but what will the young Andretti’s move have done to relations within his father’s team?
Hornish was fourth aheadof Patrick and Wheldon. Dixon now has 560 points to Franchitti’s 556, with Kanaan back on 498 and Wheldon 414.
There are only two races left in the championship – the next is at the Belle Isle street course in Detroit next weekend before the finale at Chicagoland one week after that.
Photo: IRL / Ron McQueeny