The Spaniard admits that he risked locking up and hitting team-mate Charles Leclerc when he dived down the inside and took a very tight line into the left-hander at Turn 1.
It paid off as he passed Hamilton and jumped from fourth to third. However, the Mercedes driver ultimately had more pace, and a few laps later Sainz was pushed back to the fourth place he still held at the flag, before Hamilton’s post-race disqualification gifted him third again.
Asked by Motorsport.com about the move, he said: “It was tight because if I lock up or anything, I take Charles and Lando with me because there's such a tight angle, but I did a bit of Monaco Loews turn and made it work! It's always tight here the first lap, very tight."
Sainz was satisfied with his race, not least because in an event without safety cars he finished just 15.1 seconds behind winner Max Verstappen, and 4.4s behind Norris.
After the flag, he told the team that he was “surprised” to be so close to the McLaren.
“Honestly, if you would have told me on Saturday after seeing how much we struggled against the McLaren and Mercs that today we would be fighting them, I would have been quite happy,” he said.
“Especially because Lando at one point in the first stint was very far ahead, and then we must have done a good job catching back, with a good, solid pace. I think today we didn't invent anything, we just did our race, and we were very quick, so I'm quite happy with that."
After losing out in qualifying to Leclerc, Sainz felt that he performed better in the sprint and the main race, adding: “I think in the race I've been relatively stronger this weekend. Something to look into qualifying, because at the last couple of races, my qualis haven't been anything special.
“But in the race, I'm quick, I was quick in Suzuka, quick here, and now I need to focus on getting my quali pace back and keep doing a good job in the race because the race pace is definitely solid."
Unlike Leclerc, Sainz ran the default two-stop strategy, and while his team-mate was left frustrated as he fell down the order, the Spaniard had no complaints.
"I think we did a good job,” he added. “Very early on because of trying to keep up with Lewis and Max and keeping the DRS. I destroyed my front tyre in the first sector trying to keep up on DRS.
“And for me, it was clear two-stop as soon as I opened up that front tyre, I was definitely asking for a two, and from there onwards honestly a two felt like I could push on the tyres."
Mercedes debuted its latest upgrade package at the Circuit of the Amercias, with Hamilton praising the added confidence it gave him. With Ferrari trailing by 22 points in the battle for second in the constructors' standings, Sainz conceded that overturning this deficit is now a harder task.
"Yeah, I agree,” he said when asked about the subject. “But given our limitations with this car, how poor our ride is and how much we're bouncing, I expected our tyre deg and our race pace not to be great this weekend.
"We just suffer a lot with this, not bouncing, but a poor ride that we have in our car.
“And yeah, if I would have had a bit more time on a non-sprint weekend I think we could have made the car definitely a bit quicker, and a bit better for the race. Even though Merc has done a step, and I think it will be very tough at the end of the season."