Yamaha's Maverick Vinales concluded the 2019 MotoGP pre-season fastest of all on a crash-strewn final day of action in Qatar.
Top spot changed hands numerous times across a day most focused on race runs, with Vinales heading Yamaha stablemate Fabio Quartararo [Sepang Racing Team] by 0.233 seconds with a 1:54.208s.
Just Andrea Dovizioso and Marc Marquez had put times on the board at the end of the first hour of the session, with the Ducati man setting the early pace at 1:58.692s, before Marquez moved clear with a 1:57.871s.
The Honda rider improved to a 1:56.450s soon after, before Sunday pacesetter Alex Rins usurped him on his Suzuki by 0.061s.
As the third hour began, Dovizioso's Ducati team-mate Danilo Petrucci shot to the top of the pile with a lap of 1:55.842s, though Rins would reclaim top spot 20 minutes later by just over half a second.
Rins was deposed a further 20 minutes later by rookie team-mate Joan Mir, though the pair soon swapped places as Rins clocked the first sub-1:55s lap of the day with a 1:54.852s.
Petrucci put his GP19 back on top with two hours and 40 minutes of the session remaining with a 1:54.818s, while Marquez slotted into second, missing out by 0.020s.
The reigning world champion demoted Petrucci on his next tour with a 1:54.613s, but would suffer his second crash of the test not long after. He walked away unscathed from a Turn 6 tumble.
Vinales proceeded to set the best lap of the test moments after Marquez went fastest of all, with the Yamaha rider edging ahead with a 1:54.555s.
He would improved to a 1:54.208s on his next tour, and would remain the benchmark through to the chequered flag despite his best efforts to better it.
Quartararo was comfortably top rookie on his SRT M1 in second in the end, with Marquez completing the top three.
Valentino Rossi was cast 1.2s adrift in 19th after Sunday's running, but made a big turn in pace on Monday to end up fourth and 0.443s behind works team-mate Vinales.
A further 0.002s behind completing the top five was Honda's Jorge Lorenzo, who added his name to the lengthy list of crashers on Sunday, which also included LCR Honda duo Cal Crutchlow [17th] and Takaaki Nakagami, and KTM's Johann Zarco [21st].
Franco Morbidelli made a late jump to sixth on the sister SRT bike, with KTM's Pol Espargaro a tenth back in seventh. Nakagami, Petrucci and Pramac's Jack Miller completed the top 10.
Suzuki duo Rins and Mir were shuffled back to 11th and 12th respectively, the former crashing late in the session. Tito Rabat [Avintia] was another faller in 14th, the Spaniard sandwiched between Francesco Bagnaia [Pramac] and Dovizioso.
