to view full Race results for the Catalunya MotoGP.
Marc Marquez prevailed in a gripping battle of wits with his Repsol Honda team-mate Dani Pedrosa to cement an astonishing seventh straight premier class win in the Catalunya MotoGP.
The pair locked horns on a dramatic final lap, with Pedrosa gifting second position to Movistar Yamaha's Valentino Rossi when he touched Marquez's rear wheel through T10 in his efforts to find a way through.
Remarkably, Pedrosa managed to remain upright, but the Spanish star's chances of ending defending champion Marquez's dominant winning streak were over as he ran out wide, enabling Rossi to swoop for a fine runner-up position.
Jorge Lorenzo finished outside the rostrum places in fourth without ever threatening the top three, while LCR Honda's Stefan Bradl and Aleix Espargaro on the Forward Yamaha crossed the line on their own as they completed the top six.
Played out against an ominous backdrop of lightning in the final stages of the race and with the threat of rain at one point looking certain to force the riders into pit lane to switch bikes, the Catalunya MotoGP was an electric showdown with the on-track action to match.
A frenetic start set the tone for the rest of the race with Pedrosa appearing to have grabbed the lead as they powered towards the first corner.
However, it was the flying Lorenzo who seized the initiative with a stunning move on the brakes around the outside of his Honda rival.
Rossi slotted into third but gained a position with a move on Pedrosa at T4 to take up the pursuit of Lorenzo. Marquez was fourth followed by Bradl and Andrea Dovizioso.
Defending champion Marquez quickly moved into third, slipping past Pedrosa at the end of the start/finish straight on the brakes to sit behind the two factory Yamahas.
The top five were already making a break from Aleix and Pol Espargaro, with Cal Crutchlow down in 11th position and Bradley Smith 12th on the Monster Yamaha Tech 3 in the opening laps.
Rossi briefly took the lead from his team-mate at T3 before Lorenzo hit back at the next corner, but Rossi would not be outdone as he forced his way back into the lead to take up the running once more.
With Rossi opening a gap of a few tenths at the front, Marquez and Lorenzo exchanged passes on lap five while Pedrosa climbed to third on lap six with a pass on Lorenzo into T1.
Bradl lost time on the LCR Honda with a mistake on lap seven causing him to run wide and he became separated from the leading group as a result.
Marquez then made an error on lap eight at T5, running wide and allowing Pedrosa through into second place. The 21-year-old quickly made amends though with an aggressive move on Pedrosa to reclaim the position.
At the half-way stage of the race Marquez was fortunate to avoid ramming Rossi as he ran in too hot behind the Yamaha rider at T1, running off the track before re-joining in third behind Pedrosa.
He was soon back into second after another forceful pass on his team-mate and began chasing Rossi.
With lightning reported and angry dark clouds in the skies above adding to the drama on track, the action intensified with Marquez hitting the front for the first time at T1.
However, both Marquez and Pedrosa put their hands up as if in response to falling rain and it seemed as though the riders would pit at the end of the lap to swap machines.
Rossi, though, showed no such concern and seized the lead again but with six laps remaining the Italian legend allowed Marquez too much room at T1 and dropped to second.
The nine-time world champion led again on the next lap at T4 but ran wide, with Marquez taking up the running once more.
Any hopes Lorenzo had of securing a rostrum were virtually ended as he ran wide at T10 with four laps left as he held station in fourth place.
As the race reached a climax, Pedrosa emerged as the biggest threat to Marquez as he dived under Rossi into T1 and immediately began to pressurise his young team-mate.
Rossi was never able haul himself back into a position to challenge the top two but on a pulsating final lap he capitalised on a mistake by Pedrosa to seal an unlikely runner-up finish.
Pedrosa was desperately seeking a way past Marquez and forced his way into the lead at T1, only for Marquez to go top again at T3 with a spectacular pass.
The Honda duo traded blows again through T4 and a determined Pedrosa lined himself up for once final attack at T10, where he touched the rear of Marquez's Honda and blew his hopes of victory in a breath-taking finale.
Marquez and his brother Alex, who won the earlier Moto3 race, made history as they became the first brothers in 65 years of Grand Prix racing to win races on the same day.
Outside the top six, Pol Espargaro on the Monster Yamaha Tech 3 was a fine seventh followed by leading Ducati rider Andrea Dovizioso and Andrea Iannone on the Pramac machine in ninth.
Bradley Smith finished 10th, while there was more disappointment for Cal Crutchlow, who pulled into pit lane on lap 10.
Alvaro Bautista was a retirement on the Gresini Honda, while Karel Abraham was a faller on the Cardion AB Honda in the early stages.
Scott Redding took an excellent 12th on the Open class Honda behind Yonny Hernandez (Energy TI Pramac Ducati) and ahead of Nicky Hayden on the Drive M7 Aspar Honda.
1. Marc Marquez
2. Valentino Rossi
3. Dani Pedrosa
4. Jorge Lorenzo
5. Stefan Bradl
6. Aleix Espargaro
7. Pol Espargaro
8. Andrea Dovizioso
9. Andrea Iannone
10. Bradley Smith
11. Yonny Hernandez
12. Scott Redding
13. Nicky Hayden
14. Michele Pirro
15. Hiroshi Aoyama
16. Broc Parkes
17. Michael Laverty
18. Colin Edwards
19. Hector Barbera
20. Michel Fabrizio
Mike Di Meglio