RACE 1

Scott Dixon won for the fourth time – the third on a street circuit – in Race 1 of the Shell and Pennzoil Grand Prix of Houston to slice Helio Castroneves’ championship points lead from 49 to eight heading into the penultimate race of the IZOD IndyCar Series season.

The second 90-lap race on the 1.683-mile, 10-turn course is at 1 p.m. (ET) Oct. 6. The final race Oct. 19 at the 2-mile Auto Club Speedway oval in Fontana, Calif., will mark the eighth consecutive year that the series title has been decided in the finale.

Castroneves started a season-low 21st and finished 18th in the No. 3 Shell Pennzoil Team Penske car. He developed a shifter issue early in the race and dropped nine laps behind during repairs on pit lane. He had been the only driver to complete all 2,003 laps entering the race.

Dixon has an average finish of 2.2 through five of the six races that constitute doubleheaders and 7.1 on street circuits. He can earn another SONAX Perfect Finish Award, adding $50,000 to the $100,000 he earned by sweeping the races at Exhibition Place in Toronto in July, with a victory in Race 2. Dixon's next victory will tie Al Unser Jr. for sixth on the all-time Indy car list with 34.

Dixon, who started third, pitted on Lap 64 just before a full-course caution for the stopped car of Oriol Servia. Will Power in the No. 12 Verizon Team Penske car regained the point on the exchange, but he had to pit for the final time on Lap 73, which put Dixon back at the front of the field for the duration. He won under caution.

Simona De Silvestro finished a career-high second and Justin Wilson earned his fourth podium finish of the season.

Also on Oct. 5, Sage Karam held off Schmidt Peterson with Curb-Agajanian teammate Gabby Chaves to win the Firestone Indy Lights Grand Prix of Houston.

Karam’s first road/street circuit victory, while three of the four fellow title contenders faltered in the penultimate race of the season, set up a winner-take-all scenario with Chaves at Auto Club Speedway on Oct. 19. Karam leads by 16 points.

Karam, who started from the pole in the No. 8 Schmidt Peterson with Curb Agajanian after the lineup was set by entrant points, led every lap in the timed race on the 1.683-mile, 10-turn course.

Carlos Munoz, who entered the race two points behind Karam, finished a season-low 12th and was eliminated from title contention. So was Jack Hawksworth, who was 11 points behind but finished sixth. Peter Dempsey also was eliminated.

RACE 2

Scott Dixon took advantage of Helio Castroneves' discouraging race weekend to slide into the driver's seat of the IZOD IndyCar Series championship chase.

Dixon won Race 1 of the Shell and Pennzoil Grand Prix of Houston on Oct. 5 and was runner-up to Will Power in Race 2 to take a 25-point lead heading over Castroneves into the MAVTV 500 INDYCAR World Championships on Oct. 19 at the 2-mile Auto Club Speedway oval in Fontana, Calif.

It will mark the eighth consecutive year that the series title will be decided in the finale.

Power overtook Dixon's No. 9 Target Chip Ganassi Racing car in Turn 3 of a Lap 40 restart and held on for his second victory of the season (20th of his Indy car career) as the yellow flag flew behind them on the final lap of the 90-lap race for heavy contact involving the cars of Dario Franchitti, Takuma Sato and E.J. Viso.

Franchitti, a four-time series champion and three-time Indianapolis 500 winner, was admitted awake and alert to Memorial Hermann Texas Medical Center in Houston for a concussion, spinal fracture that will not require surgery and a fracture to the right ankle.  He will be kept overnight. Sato and Viso were evaluated at the scene and released.

"On the last lap I caught the marbles and brushed the wall and lost momentum," said Sato, the pole sitter for Race 1 in the No. 14 ABC Supply car for A.J. Foyt Racing. "A couple cars passed me as I was offline and in Turn 5. I got very loose and Dario and I came together.”

Dixon started next to Castroneves on Row 1 for the standing start as the starting grid was set by entrant points after a rainstorm washed out the morning 30-minute qualifying session.

"Another win would have been nice," Dixon said, "but a decent weekend and a good turnaround for us in terms of points. It's still going to be a tough weekend at Fontana. Twenty-five points, it can go anybody's way."

Castroneves entered the third doubleheader of the season with a 49-point advantage. After qualifying a season-low 21st and finishing 18th in Race 1, combined with Dixon's victory, Castroneves' lead was sliced to eight. A shifter issue early in Race 1 required repairs on pit lane that dropped Castroneves nine laps down. In Race 2, a broken gearbox housing left Castroneves' No. 3 entry stranded in Turn 6 of the 1.634-mile, 10-turn circuit.

The crew returned the car to its temporary garage area to replace the gearbox and rear suspension, and Castroneves rejoined the race on Lap 47 (36 laps down to race leader Power) and finished 23rd.

"We’ve had great luck for most of the season. Now, in a weekend, everybody’s dream has become an interesting scenario,” said Castroneves, who had a streak of 12 consecutive top-10 finishes end in Race 1. "I will tell you one thing, this team is a testament to never giving up and I have faith in these guys that they are going to do everything they can to make it happen in Fontana.”

Castroneves was among 23 drivers who tested at the venue Sept. 24 in preparation for the 200-lap twilight race.

"The good news is we had a test there and it was extremely good," Castroneves continued. "It's going to be a heck of a race."

James Hinchcliffe finished third for his first podium since Iowa in June and Justin Wilson followed up on his fourth podium of the season with a fourth-place finish. Sebastien Bourdais advanced from the 13th starting position to finish fifth. Oriol Servia gained the most positions, climbing from 21st to finish seventh in the No. 4 National Guard Panther Racing car.

Here is video of Franchitti's crash on the final lap of race two:

Video courtesy of NBCSN