Defending world champion Lewis Hamilton set the fastest time around the street circuit of Monte Carlo's capital during both the Free Practice sessions on Thursday, ahead of the Formula One Monaco Grand Prix.

The Mercedes driver stopped the clock on one minute, 12.106 seconds, with Max Verstappen just 0.059 seconds slower than the British driver in the first session, while Hamilton's teammate Valtteri Bottas clinched the second fastest time during the second session, on a day dominated by memories of F1 legend Niki Lauda, who died on Monday.

“It's not an easy situation to try to go back to racing, especially not in Monaco with so much media attention in front of all of you, trying to keep it together emotionally in speaking about a friend," said Mercedes Team Principal Toto Wolff after the sessions, the first F1 event after the death of Lauda. "It's so difficult for me to try to talk about Niki the icon of Formula 1, that he was. I think the biggest icon that we had," Wolff said. “My emotions are so overwhelming as a friend, The last 48 hours were terrible, I feel like a zombie."

Hamilton set the best time of the day on 1:11.118 in the second session while Bottas took the second slot, confirming the German Silver Arrows' domination so far this season.

After the second session, Wolff spoke publicly for the first time since his friend, the team’s non-executive chairman and triple F1 world champion died. Wolff said he felt like “we have lost what was the heart and soul of Formula 1.”

Monaco-born Charles Leclerc, racing around the streets he has known since he was a child, having been born in Monte Carlo, came in fourth in the first session at the wheel of his Ferrari, once again causing the Italian team a problem given that he was once again faster than his teammate Sebastian Vettel who is the team's lead driver but who only managed to come in fifth-fastest.

However, Vettel set the third fastest time in the second session, ahead of Pierre Gasly of Red Bull.

The normally luxurious streets of Monte Carlo are notoriously unforgiving and many drivers lost time as they made mistakes on the as-yet green track.

Turn one, better known by its name of Sainte Devote after a church at the end of the opening straight next to the pit lane, saw Vettel, Bottas, Lando Norris and Lance Stroll all skim close to the crash barriers.

The Haas team had to rely on the FIA Race Direction to help communicate with its two drivers, Kevin Magnussen and Romain Grosjean, who both suffered radio and telemetry data transmission failures in the 24th minute of the session.

The only thing that could be done was to black-flag the teammates so they could come into the pits as soon as possible.

It took the team's mechanics some 15 minutes to repair the problem but this was still enough to enable Magnussen to finish eighth fastest and Grosjean was 10th in the first session.

Hamilton was able to fit in 46 laps of practice, while Bottas managed 42 in the first session.

This was in stark contrast to McLaren driver Carlos Sainz who had to wait for much of the first session as mechanics worked to fix power unit problems.