The Spaniard led every lap of a slow-burning race from pole position, and delivered a tactical masterclass to ward off a rapidly approaching Mercedes duo in the race's second half by employing Lando Norris as a bodyguard.
Mercedes had forecasted a potential strategic advantage after qualifying on Saturday, with Russell stating that he had saved an extra set of medium tyres available for the race should there be an opportunity to two-stop.
Esteban Ocon's stopped Alpine presented that opportunity, and the following virtual safety car ensured that both Mercedes drivers could pull in for a cheaper pitstop on lap 44 and claim their fresh sets of tyres.
This gave them a distinct advantage and, although they ceded track position to drop into fourth and fifth, Russell and Lewis Hamilton were around two seconds per lap quicker than the cars ahead.
Charles Leclerc, who had dropped positions amid the round of pitstops under the earlier safety car having got up to second at the start, was first up for the two Mercedes, who picked him off swiftly and rapidly began to reel in Norris ahead.
Recognising that his best chance of victory was to ensure Norris had the tools to defend, Sainz backed off to ensure Norris had DRS for the closing stages, which protected the Briton against the threat from his countrymen behind.
Source: Autosport