Repsol Honda's Marc Marquez cemented his place at the top of the MotoGP standings with victory in Indianapolis.
Marquez comfortably beat team-mate Dani Pedrosa, their third one-two of the season, with Yamaha's Jorge Lorenzo making it an all-Spanish podium.
Having won at Laguna Seca last week and in the early-season event in Texas, it completed a clean sweep of this season's American races for 20-year-old Marquez.
Pedrosa slipped ahead of Lorenzo early on the penultimate lap and held on to second, over two seconds ahead of Lorenzo but almost three and a half behind Marquez.
Lorenzo's team-mate Valentino Rossi was fourth with Cal Crutchlow fifth for Monster Yamaha, the Italian overtaking both Crutchlow and Alvaro Bautista on the last lap.
The top five racers on the day occupy the same positions in the season standings, separated by 61 points with Marquez 21 clear.
British rookie Bradley Smith (Monster Yamaha) also made a late move, overtaking Ducati duo Nicky Hayden and Andrea Dovizioso at the last corner to snatch eighth place.
Earlier in the day, MotoGP organiser Dorna confirmed the series would return to Indianapolis next season for the final year of the track's existing contract and also that the two parties "have started discussions about a long-term relationship past the terms of the current contract".
Doug Boles, president of Indianapolis Motor Speedway, responded: "We are also eager to continue working with our friends at Dorna to ensure an exciting long-term future for MotoGP at the 'Racing Capital of the World'.
"I'm extremely pleased that MotoGP will be returning to iconic Indianapolis track in 2014 to bring the pinnacle of motorcycle racing to the American fans.
"The Brickyard not only attracts a great crowd every year, but its heritage and history in the world of motor racing also helps grow the popularity of MotoGP in the United States and around the world."
Leading final positions
1 Marc Marquez (Spa) Honda 44mins 52.463secs
2 Dani Pedrosa (Spa) Honda 44:55.958
3 Jorge Lorenzo (Spa) Yamaha 44:58.167
4 Valentino Rossi (Ita) Yamaha 45:12.358
5 Cal Crutchlow (Gbr) Yamaha 45:12.418
6 Alvaro Bautista (Spa) Honda 45:12.524
7 Stefan Bradl (Ger) Honda 45:17.305
8 Bradley Smith (Gbr) Yamaha 45:33.153
9 Nicky Hayden (USA) Ducati 45:33.164
10 Andrea Dovizioso (Ita) Ducati 45:33.286
11 Andrea Iannone (Ita) Ducati 45:52.131
12 Aleix Espargaro (Spa) ART 45:59.113
13 Colin Edwards (USA) FTR-Kawasaki 46:01.925
14 Claudio Corti (Ita) FTR-Kawasaki 46:07.670
15 Hiroshi Aoyama (Jpn) FTR 46:12.622
1 Marc Marquez (Spa) Honda 188pts
2 Dani Pedrosa (Spa) Honda 167
3 Jorge Lorenzo (Spa) Yamaha 153
4 Valentino Rossi (Ita) Yamaha 130
5 Cal Crutchlow (Gbr) Yamaha 127
6 Stefan Bradl (Ger) Honda 93
7 Andrea Dovizioso (Ita) Ducati 87
8 Alvaro Bautista (Spa) Honda 81
9 Nicky Hayden (USA) Ducati 72
10 Bradley Smith (Gbr) Yamaha 59
1 Honda 226pts
2 Yamaha 204
3 Ducati 90
4 ART 58
5 FTR 26
6 FTR-Kawasaki 20
7 Ioda-Suter 18
8 PBM 3
9 FTR-Honda 2