Yamaha's Valentino Rossi believes MotoGP's newest race winner Alex Rins is a threat for the title this year after the Suzuki rider's breakthrough success at Austin.
Rins overtook Rossi in the closing stages of Sunday's Austin race to secure his first premier class win, and Suzuki's first triumph since the 2016 British Grand Prix.
After Marc Marquez crashed from the lead, Rins is now third in the riders' standings, five points behind Ducati's new leader Andrea Dovizioso.
Asked whether he saw Rins as a possible title rival, Rossi cited the Spaniard's upturn in form since the second part of the 2018 campaign, which Rins concluded with three podium finishes from four races.
"I think [of him] for sure as an opponent for the title, because it's not one race, he was strong in the second part of last season," said Rossi, who is second in the standings.
"He is always near the front. He's always fast in the races, even if he sometimes struggles in practice.
"I'm happy for this, because I'm more or less in the same boat!
"He rides in a clever way, he's very smooth with everything, this is very important for saving the tyre in the second half of the race.
"He's very difficult to beat."
Rins acknowledged a title bid was possible if Suzuki maintains its form.
"The results are showing [this is possible]," he said.
"If we continue at this level we will see. We do not rule out anything, now we come to Europe and there we are strong."
Despite Marquez's crash, Rossi still believes the Honda rider is favourite for the title.
"There are four riders with four different bikes in the first four places in the world championship, so it's very even," he added.
"The rules have made weekends very lively and sometimes it can be the case that one of the fastest riders is outside Q2, like what happened to Dovizioso [who started the Austin race 13th].
"This is good, but we must say that the situation is only so balanced because Marquez crashed. Otherwise Marquez would be out on his own in front.
"Marquez remains the favourite, because in Qatar he was second, in Argentina he dominated, and here [in Austin] he would have won if he did not crash.
"So yes, he remains the favourite."