Ferrari's Sebastian Vettel laid down the marker in the second practice session of the Hungarian Grand Prix.
Vettel is bidding to bounce back from his nightmare race in Germany after he crashed out from the lead to hand the championship advantage back to Hamilton.
Ferrari arrived here hoping that the slow-speed Hungaroring circuit would suit their machinery, and so it proved as Vettel saw off the Red Bull duo of Max Verstappen and Daniel Ricciardo to claim top spot.
Verstappen, however, was just seven hundredths of a second down on Vettel to suggest that Red Bull could take the fight to Ferrari this weekend.
As for Hamilton and Mercedes, they appear to have their work cut out at the sport’s final round before the month-long summer shutdown.
Hamilton, who holds a 17-point lead over Vettel, was fifth in both practice sessions, and finished an alarming three quarters of a second behind Vettel in the afternoon running.
His Mercedes team-mate Valtteri Bottas was even further back in sixth with the Silver Arrows, as has been the case in recent seasons, off the pace at this slowest of the non-street circuits.
Traditionally, Ferrari also tend to hold a little in reserve during practice, so Vettel’s speed is likely to be a concern to their rivals.
Fernando Alonso’s McLaren team have brought a heavily-revised car to Hungary, but there was little improvement for the Spaniard.
Alonso, who celebrates his 37th birthday on Sunday, was only 12th in the order, two seconds down on Vettel.
His team-mate Stoffel Vandoorne has been desperately out of sorts in recent races, and the Belgian was second-to-last in the standings, nearly a full second behind Alonso. He was also fortunate to avoid crashing into the barriers after spinning off at turn five.
Elsewhere, Romain Grosjean was the best of the rest as he finished seventh for Haas. Carlos Sainz was eighth for Renault ahead of Toro Rosso’s Pierre Gasly. Esteban Ocon completed the top 10 in his Force India.