Monaco is back on the calendar for 2021 after an enforced absence in 2020 that broke a consecutive streak of over 60 Grands Prix.
Both drivers wasted no time in getting up to speed with the Monte Carlo street circuit, heading straight out on Hard tyres to establish a baseline for the AMR21.
Sebastian would set a series of increasingly quick laps as he initially placed within the top five, eventually settling into eighth with a 1.14.209 effort.
Lance would remain close to the pace of Sebastian throughout the opening half-hour and posted a then-personal best of 1.15.108 before both drivers ended their 14-lap run.
The circuit was becoming increasingly busy and Fernando Alonso's minor scrape with the wall at the final corner brought out the first Virtual Safety Car of the weekend.
Monaco Grand Prix
Get ready for this weekend's Monaco Grand Prix with our in-depth preview. Discover the history of Monte Carlo, the challenges of a lap of the track and the key talking points for the race around the Principality.
Following the interruption, both drivers returned to the circuit after bolting on a set of Mediums, the tyre of choice for the remainder of the session.
After continuing to evaluate the AMR21, Sebastian set his best time of the session in 1.13.732, while Lance left it late in the session to improve his best to 1.14.090. Sebastian ended free practice one in eighth and Lance finished 11th.
Both drivers would begin second practice with shorter runs on Medium tyres, completing 10 laps each, before switching to the Softs for the first time this weekend.
Using the benefit of the faster compound, Sebastian set his fastest time, a 1.12.982 effort, with just under half the session remaining to secure 10th on the timesheets.
His session was then affected by something getting stuck in his eye, but Sebastian was able to push on with his run plan.
Lance would lap just over three tenths off Sebastian’s best to post a 1.13.195, sealing 13th.
The pair would return to the garage shortly after, but the grid's programme was then disrupted by Mick Schumacher’s brush with the wall that brought out a Red Flag in the final 10 minutes.
The duo completed 118 laps, giving the team plenty of data to pour over ahead of Qualifying on Saturday.
Sebastian: "I think everybody is happy to be back here at this special track and it is great to see fans in the grandstands, even though the numbers are still limited.
"The morning session went well, and I got into a rhythm quickly, but the afternoon was more complicated because I got something in my eye, which was quite uncomfortable and caused my eye to tear up.
"As usual, it is very close in the midfield, which means getting everything perfect on Saturday afternoon, and being lucky with the traffic, is what matters.
"I feel happy with the work we did today and if we can get everything together over the weekend, we can hopefully be near the front of the midfield group."
Lance: "It is great to be back here in Monaco, especially after the race did not take place last year. I had a lot of fun out there today – building up speed and getting close to the walls.
"It was very busy on track, with a lot of traffic, and not easy to find free air, which is always a major factor on Saturday and Sunday, too. The sessions went smoothly, giving us lots of information and things to improve before final practice.
"There is a chance to catch our breath tomorrow with a quiet day, but we still have some engineering meetings to see what ideas we can come up with ahead of qualifying."
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