The Honda star, who reeled off consecutive wins in the first 10 races of 2014, was back in business in the Austin, Texas after a sluggish season-opening fifth in Qatar.
The 22-year-old is lying third in the standings with 36 points, five behind nine-times champion Valentino Rossi, who came third last weekend to add to his win at Losail.
Ducati’s Andrea Dovizioso, on 40 points, splits the pair after two seconds.
Marquez, though, will be the man to beat again on Sunday at the Termas de Rio Hondo circuit where he swept all before him in 2014 on Argentina's return to the MotoGP calendar for the first time in 15 years.
“In Qatar I didn't get the result I would have liked,” he wrote in a blog for his team, “but we weren't too worried because the feeling in general was positive, and after a good weekend in Austin, I’m feeling relaxed and confident again.
“We've already seen that the Ducatis are putting up a good fight, that Rossi is very fast, and I don't doubt that Jorge Lorenzo will also move on up and fight for wins. So we have to concentrate 100 percent.”
Looking back on last weekend he mentioned his remarkable pole, posted on his spare bike with only minutes left in qualifying.
“It was a moment of pure adrenalin, there's no other way to describe it,” he wrote. “When I stopped the bike I looked at the time remaining and tried to mentally calculate it as quick as possible. I saw that I had time to try it, not much, but it was there. That's why I didn't want to lose a single second and I ran for the second bike.
“I can't deny that was the best moment of the whole weekend, even better than the race itself.”
Dovizioso is waiting to exploit any weakness on the part of the double world champion at a track where he trailed in ninth 12 months ago.
“Last year I had a difficult race in Argentina,” he said, “We had a few technical problems, I didn't have a good feeling with the bike and the track was very dirty, so the whole weekend didn't go well.
“Now the situation is different, and I am sure that at Termas we can fight for the leading positions, as we did in the first two races of this year.”
At 36, Rossi is no spring chicken in MotoGP terms but the charismatic London-based Italian is rolling back the years at Yamaha after a frustrating spell at Ducati.
He said: “I'm happy to go to Argentina because I like the track. We hope that there will be a better condition of the tarmac compared to last year, because the track and the layout are good. It's also not a bad circuit for our M1.”
Rossi's team-mate, former champion Jorge Lorenzo, shrugged off a bout of bronchitis to take fourth in Texas and is fully recovered as he tries to improve on last year's third in Argentina.
“I hope Argentina will suit us better,” said the Spaniard. “In Termas the circuit is pretty nice to ride and last year, even if I wasn't in an optimal shape, I still managed to get on the podium. It's a fast track with very nice corners and I guess this is good news for our bike.”
Original source: Confident Marquez ready to rumble