Taking over the #51 Ferrari 499P for the second part of the three-hour session, Shwartzman set an impressive time of 1m48.559s in his first day of running in an LMH car.
The 24-year-old’s lap was fractionally faster than the time with which Will Stevens set the pace this morning in the Jota Porsche, which meant he also topped the overall order at the end of the day.
The Ferrari Formula 1 reserve driver shared the car with fellow Ferrari factory driver Lilou Wadoux, who managed to improve her time by nearly seven seconds in the afternoon after a short run in the morning session.
Wadoux, who also ran in the Toyota GR010 Hybrid at the same test last year, posted a best time of 1m49.488s, which was nine tenths slower than what Shwartzman managed later in the session.
Second place in the afternoon went to Jota, with Norman Nato setting a time of 1m49.130s after driving the team’s customer Porsche 963 on his own in the session.
Robert Kubica was due to appear in the car ahead of an expected Hypercar programme with Jota in 2024, but the Polish driver didn’t turn up for the test that took place a day after his LMP2 title success with WRT.
In the absence of Kubica, Nato only completed 13 laps of the track in the car that finished a season-best fourth in the Bahrain 8 Hours.
European Le Mans Series frontrunner Rene Binder propelled the other customer Porsche car of Proton Competition to third with a time of 1m50.308s.
Fellow Austrian Thomas Preining put the factory Porsche Penske car in fourth position after getting another 56 laps in the cars following an initial try-out in the morning.
The newly-crowned DTM champion put in a best lap of 1m50.603s, just under three tenths slower than what Binder managed in the Proton-run 963 LMDh.
The sole Toyota GR010 Hybrid taking part in the test was classified fifth in the hands of Lexus driver Ben Barnicoat, whose best time was 1m52.134s.
Barnicoat’s lap was just under half a second quicker than Jack Hawksworth's best effort during his turn at the wheel of this year’s championship-winning car.
Malthe Jakobsen was sixth in the best of the Peugeot 9X8s with a time of 1m51.076s, while Kyffin Simpson put the Cadillac LMDh seventh with an early effort of 1m51.380s.
The Hypercar field was propped up by Job Van Uitert in the Vanwall LMH, with the Dutchman finishing just behind the second of the two Peugeots.
WRT topped the LMP2 order with BMW factory driver Charles Weerts at the wheel of its renamed #46 ORECA, although Weerts’s time of 1m54.302s was 0.019s slower than Clement Novalak's chart-topping effort in the Inter Europol ORECA 07 in the morning session.
MotoGP star Valentino Rossi got more mileage behind the wheel of the WRT LMP2 car in the afternoon and set a best time of 1m55.118s just before a red flag, which put him at the top order until Weerts took over the car for the final parts of the session.
Novalak put Inter Europol second in the session after getting very close to his morning benchmark, as Daniel Schneider finished fourth and last behind the Prema of PJ Hyett in the United Autosports ORECA.
The last-ever official session for GTE cars was topped by Lorenzo Patrese in the Richard Mille AF Corse Ferrari GTE.
Patrese set a time of 1m58.261s to beat the similar AF Corse Ferrari of Nicola Marinangeli by almost two seconds. Timur Boguslavskiy was another second behind in third in the Corvette C8.R.
The only red flag of the day was brought out by Christoph Ulrich in the #23 AF Corse Ferrari, who stopped on track just an hour into the afternoon session.
