The pair squabbled for fifth position in the latter stages of the race at the Circuit of The Americas, the Ferrari driver getting alongside at one point in their duel.
On the inside, Ricciardo held his line, only for his left-rear wheel to make contact with his rival.
It prompted a terse response over the radio from Sainz, who claimed the contact was deliberate.
“We obviously went side-by-side, and a little bit of banging wheels,” Ricciardo said of the incident.
“It was very fun, and [I] needed to hold on for everything I could.
“Obviously you don't deliberately try to go into someone, but that's obviously a bit of a bit of rubbing racing.
“And when you put yourself on the outside, obviously you're a little bit more exposed.
“Nothing was deliberate, but I guess it's the risk that he ran by trying on the outside.
“That's cool, I'm happy to be dirty,” he added when told of Sainz's radio call.
“I'm a nice guy, so being dirty every now and then is alright!”
“The first lap was a lot of fun,” Ricciardo said of the early scrap with Sainz.
“I got Carlos I think on the start, then he got me back with a good move [around the] outside of [Turn] 6 into 7, and then I got him back Turn 17 on the inside.
“It was three kind of changes in position on the first lap, [which] was cool, but that was crucial for me to get a top five.
“Obviously that's something we've got to still try to find but to beat one of them is quite rewarding.”
It was a result that helped McLaren maintain a slender advantage over Ferrari in the drivers' championship, its margin now reduced to just 3.5 points.
Formula 1 next heads to the Mexico City Grand Prix on November 5-7.