The latter phases of the grand prix at Marina Bay kicked into life when Esteban Ocon's stranded Alpine produced a virtual safety car, prompting the two Mercedes drivers to stop for a set of fresh medium tyres.
As George Russell and Lewis Hamilton hacked away at the leaders' advantage to bring themselves into winning contention, Sainz asked to be kept abreast of the gap to Norris so that he could reduce his gap out in front to keep his former team-mate in DRS range.
This ensured that Norris had something to defend himself with and, after a Russell assault with three laps to go, Sainz had to back off again to keep pulling the McLaren driver along.
Sainz explained that this was a strategy he had in the back of his mind, and required full commitment on his end to make it work out properly.
"The strategy I had to give Lando a bit of a cheeky DRS boost, that helped us to keep them behind," Sainz explained. "This is a sort of strategy that you always keep in the back of your head on tracks like Singapore, that might come useful at some point.
"The thing is, obviously it's easy to think about and it's easy to have it in mind. But it's a lot more difficult to execute it, because it does put you under some extra pressure and it comes with its risks.
"It's all about having that commitment to do it and to put yourself under that extra risk. But I felt like that was my only real chance of winning the race, and I wanted to win.
"When I had that 1.3, 1.4-second gap to Lando after he defended into Turn 16, to take the decision to slow down in Turn 1 and Turn 3 I was like "I hope this works" - because it could look really bad on me.
"But it worked, sometimes you need to trust your instinct, trust your feeling. I've been trusting that these last two weekends and it's working well."
Norris added that he was not planning to attack Sainz, stating after the race that his focus was on preserving second place despite his closeness to Sainz.
The Briton felt he would have been easier for the Mercedes duo to overtake if he made a late play for the lead of the race.
"Carlos played it smart," Norris stated. "There was no need for me to try and and attack him; the more I attacked him probably the more vulnerable I would have been from both the guys behind.
"We wouldn't be on the podium if I played it differently. I knew George was going to pressure me a lot, and I had to defend quite a bit into Turn 14.
"When Carlos backed off after that when it was a little bit of a gap and allowed me to get the DRS, it was very helpful. I think we together played in a smart way to get there."
