Danilo Petrucci pipped factory Ducati team-mate Andrea Dovizioso to top spot in a red-flagged MotoGP Spanish Grand Prix FP2 by just 0.097 seconds.
Petrucci guided his works GP19 to a 1:37.909s just moments before the red flag was flown to clear up debris left by crashes for Karel Abraham and Bradley Smith at Turn 5, and remained unchallenged when the session resumed.
Morning pacesetter Marc Marquez picked up where he left off in FP1 and guided his Honda to top spot with a 1:39.094s in the early stages.
Having set his FP1 best lap on an 18-lap old hard tyre, Marquez began FP2 on a fresh soft slick, and duly improved to a 1:38.408s on his second tour to maintain top spot.
Petrucci demoted him briefly with a lap just over two tenths quicker than Marquez – though the Honda man was soon back in front, edging Petrucci by just 0.050s.
Major improvements on the timesheets were few and far between in the middle part of the session, as most worked on evaluating race set-up options.
HRC test rider Stefan Bradl signaled the beginning of the time attack phase of FP2 with eight minutes remaining, as the wildcard shot up to third on his RC213V, before Honda stablemate Marquez improved at the top of the standings with a 1:38.147s.
LCR's Cal Crutchlow usurped Marquez with a 1:38.104s, though the 2018 Jerez pole man was soon beaten by Petrucci with a 1:37.909s, with team-mate Dovizioso following 0.097s behind.
Separate highside crashes for Avintia's Abraham and Aprilia wildcard Smith at the Pons corner brought out the red flag with just under three minutes left on the clock.
Both riders walked away – though Smith was taken to the medical centre – and the session was quickly restarted. However, Petrucci's benchmark came under no threat.
Dovizioso remained ahead of Crutchlow at the chequered flag, with Marquez slotting into fourth ahead of top Yamaha runner Maverick Vinales.
Fabio Quartararo fired in a late 1:38.370s on his Petronas SRT Yamaha to go sixth quickest, beating Bradl, LCR's Takaaki Nakagami, Honda's Jorge Lorenzo and fellow rookie Francesco Bagnaia on the Pramac GP18.
Valentino Rossi improved on his FP1 lap by 0.7s in the afternoon session, but this still left him outside of the provisional Q2 places in 14th, with Austin race winner Alex Rins a few hundredths further adrift in a similarly low-key 16th on the Suzuki.
Rins' team-mate Joan Mir ended the session 17th having crashed at Turn 1 at the end of FP2 due to an apparent brake failure.
Johann Zarco [20th] crashed his works KTM for a second time on Friday, coming off at Turn 2 early in FP2 just moments after Tech3 counterpart Hafizh Syahrin came off his RC16 at Peluqui.
Syahrin did not return to action after his tumble, but his Tech3 team later confirmed he came away relatively unscathed.
