Mercedes continued to reign supreme in Barcelona in Friday's second practice, with Lewis Hamilton taking over from teammate Valtteri Bottas.
Warmer temperatures at the Circuit de Catalunya meant slightly slower times for the front runners, with Hamilton's 1m16.883 edging Bottas by 0.287s, while Red Bull's Max Verstappen remained the pair's closest rival in third.
Renault's Daniel Ricciardo and Haas' Romain Grosjean were welcome sights among the top five, with Ferrrai's Charles Leclerc clocking in sixth 1.264s down on Hamilton's best.
The only change worth a mention that took place at the start of FP2 was George Russell collecting his car back from Williams rookie Roy Nissany.
Ambient and track temperatures were boosted by a few degrees by the Spanish sun, implying that the afternoon session would perhaps not be as fast as FP1, with drivers inclined to shy away from Pirelli's C3 soft tyre.
McLaren's Lando Norris and Ferrari's Charles Leclerc established the early benchmarks, but 15 minutes in, Hamilton went clear of the latter by a full second.
The field was fitted with a mix of all three compounds - mediums, hards and softs - according to the teams' various plans. But a hot run by Bottas on the soft rubber put the Finn in command with a 1m17.170s.
However, Hamilton made even better use of his own set of red-walled softs to overhaul his teammate by 0.287s, dipping into the 1m16s.
Behind the two Mercedes chargers, Verstappen was followed by Renault's Daniel Ricciardo, while Haas' Romain Grosjean continued his morning form in fifth.
The soft tyre was the norm session flew past its half-way mark and drivers evaluated the compounds durability or conducted qualifying simulations, but the running remained unchanged up front.
But with under 30 minutes to go, drivers switched to long runs with the medium rubber in widespread use.
Changes were therefore few and far between as the first day of practice in Barcelona came to a close, Hamilton picking up the baton from Bottas and Verstappen remaining as Mercedes' closest challenger.
Ricciardo and Grosjean rounded off the top five while Leclerc was Ferrari's fastest charger once again as Vettel ended his session a lowly P12.
McLaren's Carlos Sainz improved on his morning form, clocking in 7th in front of Perez, Ocon and Alphatauri's Pierre Gasly.
At the tail end, George Russell was outpaced for the first time this season by his Williams teammate Nicholas Latifi, the Briton complaining of "zero grip" on both axles.
But at the end of the day, it was business as usual for the mighty Mercedes squad on the first day of running in Barcelona.