"So tomorrow I'll start from fourth".
Iannone tried to keep pace with the world champion but began to slip back as Marquez edged ahead by just over a second.
The Suzuki man's time in the lead proved short-lived however, as Marquez got by at Turn 12 on the opening lap.
Marc Marquez remains untouched in COTA as he takes his sixth straight win at Austin, ahead of Maverick Vinales and Andrea Iannone.
A bolt off his starting line saw Marquez muscle past Vinales and into second behind Suzuki's Andrea Iannone of Italy by the first turn.
Marco Bezzecchi does a wheelie at the end of the Moto3 in Argentina Credit Getty Images South America /Mirco Lazzari
Marquez, a four times world champion, has yet to win this season but will still fancy his chances from fourth place at a favourite track.
Iannone kept the Honda rider honest in the very early stages, and even mounted an assault on the Spaniard's lead at Turn 11 on the third lap. Marc Marquez won the race a country mile ahead of Vinales and Iannone. Vinales took the second spot from Iannone and stayed there. "But in the race, I hoped and expected to be a bit stronger to fight for the podium".
After much uncertainty, Honda rider Dani Pedrosa did participate in the Austin GP with a post-surgery right wrist and finished at P7, quite commendable to say the least. Danilo Petrucci, Pol Espargaro, Taka Nakagami and Alvaro Bautista compled the top 15.
Completing the top 10 were privateer Ducati pair Tito Rabat (Avintia) and Jack Miller (Pramac) and the leading Aprilia of Aleix Espargaro, who all crowded past a struggling Jorge Lorenzo (Ducati) late on.
It was an important move; with Crutchlow out of the points and Marquez a mile in front, the points for fifth were enough to give Dovizioso a slender one-point championship lead. It was mostly status quo for the rest of the race apart from a few fallers including championship leader Cal Crutchlow. In a miserable day for the British riders, Bradley Smith and Scott Redding also finished out of the points and, over the three Grand Prix classes, John McPhee was the only Brit who managed to score points over the weekend, down in 14in the Moto3 race.
Modi misled by military on 'surgical strikes': Asif
At the " Bharat Ki Baat , Sabke Saath" event in London , PM Modi said that "rape is rape" and shouldn't be politicized. Meanwhile, the flag has been replaced.