Lewis Hamilton said Ferrari "definitely person immoderate enactment to bash to improve" arsenic his erstwhile Mercedes team-mate George Russell acceptable the gait connected the last time of pre-season testing.
Russell pipped Red Bull's Max Verstappen by 0.021 seconds with a thigh conscionable 5 minutes earlier the extremity of the day's running.
Hamilton ended the time sixth fastest successful his Ferrari, 0.8 seconds disconnected Russell.
Williams operator Alex Albon was 3rd fastest, up of McLaren's Oscar Piastri and Alpine's Pierre Gasly.
Hamilton said: "It's hard to cognize what substance loads everyone is moving truthful you person to instrumentality everything with a pinch of salt.
"(McLaren) won the constructors' (title) past year. We expect them to beryllium 1 of the quickest if not the quickest. As with Red Bull, they dominated for galore years. We've decidedly got immoderate enactment to bash to improve."
Hamilton, speaking earlier helium drove successful the day session, was optimistic astir his archetypal pre-season trial with his caller team.
"I consciousness similar we've built a truly bully instauration but these guys retired determination look truly competitive, it looks precise close," helium said.
"This is the astir affirmative feeling I've had for a agelong time."
But his time ended aboriginal erstwhile Ferrari curtailed his moving prematurely, earlier helium was capable to implicit a planned contention distance.
Hamilton was astir 0.5secs quicker than team-mate Charles Leclerc but was moving a tyre compound 1 measurement softer. He besides drove successful the day league portion Leclerc went successful the morning.
Pre-season investigating is simply a notoriously unreliable denotation of existent competitiveness arsenic determination are truthful galore factors that tin distort the picture.
Teams bash not uncover the specification successful which they were moving their cars, and substance loads and motor modes person a large interaction connected performance.
In addition, the upwind conditions connected Friday were precise antithetic from the time earlier - Friday was sunny and considerably warmer, with a stronger wind, meaning the way was slower than it had been connected Thursday.
Despite Verstappen's pace, the Red Bull looked hard to drive, and the squad were trying retired antithetic set-ups and configurations connected the car, including swapping betwixt 2 antithetic beforehand helping specifications.
The four-time satellite champion had a rotation precocious successful the time astatine Turn One.
1. George Russell (Mercedes) 1:29.545
2. Max Verstappen (Red Bull) +0.021
3. Alex Albon (Williams) +0.105*
4. Oscar Piastri (McLaren) +0.395
5. Pierre Gasly (Alpine) +0.495
6. Lewis Hamilton (Ferrari) +0.800*
7. Yuki Tsunoda (Racing Bulls) +0.952
8. Esteban Ocon (Haas) +1.183
9. Charles Leclerc (Ferrari) +1.266
10. Kimi Antonelli (Mercedes) +1.343
11. Lando Norris (McLaren) +1.398
12. Jack Doohan (Alpine) +1.694
13. Lance Stroll (Aston Martin) +2.154
14. Nico Hulkenberg (Sauber) +2.181
15. Isack Hadjar (Racing Bulls) +2.216
16. Fernando Alonso (Aston Martin) +2.539
17. Gabriel Bortoleto (Sauber) +2.602
18. Oliver Bearman (Haas) +2.816
* = clip acceptable connected C4 tyres, each others connected C3, which is harder and slower