Sainz set the quickest time on the second of the three days of testing, before the season-opening Bahrain Grand Prix at the Sakhir circuit on 2 March.
However, he set his lap using the C4 Pirelli tyre, which is not available next weekend.
His Ferrari team-mate Charles Leclerc was second quickest overall, setting his best time on the final day, as did George Russell for Mercedes and Zhou Guanyu for Sauber. They all used the C4 for their fastest times.
Red Bull’s Sergio Perez (who was quickest overall in this test last year) and Max Verstappen lapped within a tenth of each other in fifth and sixth using the C3 tyre, which will be the soft next weekend.
Yuki Tsunoda was seventh for RB, the rebranded AlphaTauri team, ahead of Alex Albon (Williams), Oscar Piastri (McLaren) and Lewis Hamilton (Mercedes).
Aston Martin, Haas and Alpine ended the three days of running without a car in the top 10.
Haas F1 Team did score one victory, by recording the most laps across the three days of running, with Kevin Magnussen logging the most mileage of any driver.
At the other end of the scale, Williams was at the bottom of the chart – and fell just short of the 300 lap mark. Logan Sargeant got the least amount of running at 138 laps.