Perez, who has been a vital part of teammate Max Verstappen's past two championship wins, topped the timesheets for the team, ahead of Lewis Hamilton's Mercedes.
Red Bull's performance during the three-day testing period has left many observers convinced that the team will be challenging for the title this season.
Mercedes' Hamilton was upbeat about the new car's performance, though he acknowledged that they were not quite where they wanted to be.
George Russell, who secured his first win last year, expressed his belief that the team had improved the car over the testing period and that they were in a better position heading into the race.
Meanwhile, Ferrari's Charles Leclerc said that Red Bull looked particularly strong during testing, leaving the Scuderia with some work to do to catch up.
The team will be hoping that new chief Frederic Vasseur can bring about a change of fortune on raceday after a disappointing 2022 season.
The final day of testing saw Verstappen sit out while Perez clocked a time that was 0.359 seconds faster than Hamilton's.
Valtteri Bottas's Alfa Romeo finished third, followed by Leclerc and Carlos Sainz in the second Ferrari, with Yuki Tsunoda of Alpha Tauri coming in sixth. Felipe Drugovich, who stood in for Lance Stroll, occupied a lower position in the timesheets but could be called upon to substitute for Stroll in the event that the Canadian is unable to race.
Sergio Perez topped the timesheets for Red Bull from Lewis Hamilton's Mercedes as pre-season testing wrapped up in Sakhir on Saturday.
Perez has emerged as a crucial cog in teammate Max Verstappen's world championship success over the past two seasons.
And after three days of trying out their 2023 cars in the desert all the signs are that Red Bull will be hard to deny next Sunday in the Bahrain Grand Prix, the first of a record 23-race season.
"Red Bull seem to be very strong in these three days," said Ferrari's Charles Leclerc after Verstappen had been quickest on the first day of testing on Thursday.
"I feel we have some work to do," added Leclerc, who will be hoping new Ferrari chief Frederic Vasseur can bring a change of fortune for the Scuderia on raceday after Ferrari's title challenge last term was undone by a mix of poor strategy and reliability.
"The car is working really well," said Verstappen, who is targeting a third straight title after defending his controversially gained 2021 crown four races from the end of last season with a record 15 wins.
Testing concluded with Perez 0.359 seconds up on Hamilton as Verstappen sat out the final day.
There was an upbeat mood in the Mercedes garage with the new car performing well and showing no signs of the bouncing that dogged last year's W13.
"We're not quite where we want to be but it's a good platform to start from," commented Hamilton.
Teammate George Russell, who secured his first win in Brazil last year, said: "I believe we have improved the car over the course of testing and got the W14 in a much better window today.
"There is still plenty of work to do but we're in better shape for next week with more to come."
Valtteri Bottas's Alfa Romeo occupied third from Leclerc and Carlos Sainz in the second Ferrari, with Japan's Yuki Tsunoda (Alpha Tauri) sixth.
Further down the times in an Aston Martin came Felipe Drugovich, who stood in for Lance Stroll, missing after a cycling accident.
Drugovich, 22 and born in Brazil, won last season's Formula 2 title and is on standby to substitute for Stroll should the Canadian son of team owner Lawrence Stroll be unfit for next weekend's race.
1. Sergio Perez (MEX/Red Bull) 1:30.305 (133 laps)
2. Lewis Hamilton (GBR/Mercedes) 1:30.664 (65)
3. Valtteri Bottas (FIN/Alfa Romeo) 1:30.827 (131)
4. Charles Leclerc (MON/Ferrari) 1:31.024 (67)
5. Carlos Sainz (ESP/Ferrari) 1:31.036 (75)
6. Yuki Tsunoda (JPN/AlphaTauri) 1:31.261 (79)
7. Kevin Magnussen (DEN/Haas) 1:31.381 (94)
8. George Russell (GBR/Mercedes) 1:31.442 (83)
9. Fernando Alonso (ESP/Aston Martin) 1:31.450 (80)
10. Felipe Drugovich (BRA/Aston Martin) 1:32.075 (77)
11. Lando Norris (GBR/McLaren) 1:32.160 (37)
12. Pierre Gasly (FRA/Alpine) 1:32.762 (56)
13. Alexander Albon (THA/Williams) 1:32.793 (136)
14. Esteban Ocon (FRA/Alpine) 1:33.257 (76)
15. Nico Hulkenberg (GER/Haas) 1:33.329 (77)
16. Oscar Piastri (AUS/McLaren) 1:33.655 (44)
17. Nyck De Vries (NED/AlphaTauri) 1:38.244 (87)