Nico Hulkenberg sent Renault to the top of the timesheets on the final afternoon of the opening test in Barcelona.
Taking over from new teammate Daniel Ricciardo, the German completed his own C5 tyre run and would post a 1m17.393s, a quarter of a second faster than Alex Albon's morning benchmark in the Toro Rosso.
The French manufacturer's week was brought to an early end, however, with an apparent mechanical issue forcing Hulkenberg to stop out on track while on an out-lap.
Indeed, of all 10 teams, Renault had the least laps of any with just 58 tours of the Spanish Grand Prix circuit totalled on Thursday.
Valtteri Bottas was another afternoon driver inserting himself near the top in fourth but interestingly, he was the slowest of those to use Pirelli's fastest tyre although fuel loads may well account for that.
Mercedes' greater emphasis on performance meant their lap count was also down compared to recent days with 'only' 112 laps completing between the Finn and Lewis Hamilton.
Charles Leclerc was sixth in the Ferrari who, despite dropping down the order, can still be considered the clear leaders after the first week with his 1m18.0s set on the C3 tyre.
By the guidelines offered from Pirelli, an improvement of 1.2 seconds would be expected between the C3 and C5 meaning Leclerc's time would translate to a 1m16.8s.
In the afternoon, the Monegasque completed a race simulation as he amassed 138 laps on the final day, the third highest total.
Lando Norris recovered from his morning off at Turn 5 and also got plenty of mileage under his belt with 132 laps in the McLaren and the seventh best time.
Antonio Giovinazzi brought proceedings to a premature end by stopping on the pit-exit in the final 10 minutes but the Italian would achieve the most distance of anyone with a mammoth 154 laps in the Alfa Romeo.
The Haas drivers of Romain Grosjean and Kevin Magnussen shared driving duties, with the Frenchman finishing two-tenths ahead of his Danish teammate.
Pierre Gasly concentrated on long runs in the Red Bull with 146 laps to his name but was only 11th fastest overall.
Lance Stroll had another solid day in the Racing Point albeit a little off the pace in 12th with the two Williams drivers of George Russell and Robert Kubica both getting on track but bringing up the field.
Full results from the final day will follow below!
A fascinating start to the 2019 F1 season with plenty to mull over and consider when looking for first conclusions.
We'll be doing that over the weekend here at InsideRacing, but now the teams can enjoy a few days off before returning to Barcelona on February 26 for the final four days of action before heading to Australia!
