Mercedes and Ferrari each sported altered liveries in memory of late three-time Formula One champion Niki Lauda at the Monaco Grand Prix on Thursday.
Lauda won his first two drivers' championships with Ferrari and later served as Mercedes' non-executive chairman before he passed away this week aged 70.
Silver Arrows star Lewis Hamilton, a friend of Lauda, was excused from media duties on Wednesday, but he and his colleagues returned to action in Monte Carlo the following day.
And tributes to the Austrian were evident during two practice sessions, as Mercedes revealed a red star and a message – 'Danke, Niki' – on their W10 car.
Lauda's name adorned both Ferrari's SF90 car and senior driver Sebastian Vettel's helmet.
Meanwhile, Mercedes, who have registered five consecutive one-twos to start the season, threatened to dominate again on the track.
Red Bull's Max Verstappen separated Hamilton and team-mate Valtteri Bottas in FP1, with just 0.072 seconds between the three drivers.
And with Verstappen limited to16 laps in the second session on a circuit Red Bull usually favour, Hamilton led Bottas for a practice one-two.
Juventus and Portugal striker Cristiano Ronaldo was in attendance in Monaco to check in on defending champion Hamilton, who found time to pose for pictures with the superstar footballer.