Valentino Rossi's 110th grand prix victory was one of his most dramatic, the MotoGP legend hunting down reigning champion Marc Marquez before the pair spectacularly clashed on the penultimate lap.

While Marquez bolted to a four-second lead using the softer of his rear tyres, Rossi had fought his way through the field from eighth on the opening lap.

Crucially, the Italian had chosen the extra-hard tyre, rejected on the grid by Marquez. "When Marc decided on the hard tyre I think we have a small chance to win, because in the second half of the race I have a good pace," Rossi said.

The tide finally turned in the Italian's favour with 12 laps to go when Rossi, now into second, reduced Marquez's lead for the first time.

The Doctor then ate mercilessly into the Repsol Honda rider's advantage, attacking at the start of the penultimate lap, when he was instantly re-passed by Marquez.

Rossi made his next move under braking for Turn 5 at the end of the back straight, the pair making contact when Marquez instantly tried to cut back under Rossi at the apex. But the real drama was on the exit, when their lines again crossed and Marquez was thrown down the track after clipping the rear of Rossi's Yamaha.

"It is a shame that he crashed, but for me I think he did a mistake," Rossi declared. "Marc is a rider that always bets all-or-nothing.

"I knew from practice that I had the pace and the extra motivation is when you see the guy in front is in difficulty and you have the extra-hard tyre. So lap-by-lap he is more in difficulty.

"Also our bike was better when the rear start to slide and Marc kept getting bigger and bigger in front of me.

"I arrived to Marc and had six or seven tenths of advantage in the pace, but just two laps to go. So I tried to overtake him, but I think 'for sure now Marc will try something to stay in front'.

"But as soon I thought about that, already he touched me in the centre of the corner. He put the bike into me and I say, 'F**k! Straight away. I think you are aggressive but I don't expect so much!'

"Then when I opened the throttle to accelerate, because I want to take a small advantage before the next braking, I hear another touch. But sincerely I don't know if it was on the right or left. So I think 'maybe this [battle] will be very strong!'

"But after when I passed to the line I saw on the pit board I had an advantage over Dovi, so I think something happened and the next lap I saw his bike.

"Marc knew if I overtook him I was a little bit faster so he tried everything, but maybe a little bit too much I think."

Rossi - who has clashed with the likes of Max Biaggi, Sete Gibernau, Casey Stoner and Jorge Lorenzo during his 20-year GP career - does not believe Marquez will be shaken by the incident, but confirmed the result was psychologically significant.

"I don't think a rider like Marc is scared about this or a bad result can modify his attitude," he said. "The important things is that we demonstrated, also to him, that in the race we can be very strong. Because he is fantastic to do the pole position. But he knows, and we have demonstrated this season, that we will be there in the races."

Rossi now holds a six point lead over Ducati's Andrea Dovizioso, who inherited second place on Sunday, with Marquez 30 points behind.

"I think it will be a great [championship] battle. Now the guy who is very close is Andrea. He is just six points after for me a fantastic start. Maybe a perfect start.

"The championship is very long and Marc has demonstrated that he can recover. I expect also Iannone, Cal and Jorge - who at the beginning of the season has some problem, but he is a rider who has the potential to get better in the next race."

With two wins from three races, Rossi has already matched his 2014 victory tally.

"In Qatar the battle with Andrea was unbelievable, but the last win is always the best!" he smiled. "I'm very happy about these three races because it looks like we are very strong. We are competitive everywhere.

"We knew we had to suffer in Austin, and we suffered but we arrived third. This track on paper was a good track for Yamaha but we struggled in practice. So it was important to demonstrate we are strong in the race.

"The bike is quite slow in the straight, we don't understand why it is slower than last year, but apart from this the Yamaha works very well. We improve some points from last year, where we were in trouble especially compared to Marc. So now we can fight."

The 36-year-old has been trying to win a tenth grand prix title since 2009 - and wore the #10 on an Argentinian football shirt on the podium.

Was it a message? "No! It is just the #10 of Maradona! I had it ready for last year, but unfortunately I finished fourth. I put in my bag again and I thought maybe this year I can wear it."

Cal Crutchlow completed Sunday's podium with his first rostrum for the LCR Honda team. The fourth round takes place at Jerez, Spain in two weeks' time - the first of Marquez's home events.