Spanish Grand Prix winner Max Verstappen starred once again in Barcelona after he recorded the fastest lap of both sessions of the final day of in-season testing.
Completing 116 laps, the young Red Bull driver set the benchmark of the day with his 1:23.26m on the soft compound tyres.
Climbing into the Honda-powered McLaren for the first time since Bahrain, Belgian driver Stoffel Vandoorne was the second quickest of the day, recording a lap time of 1:24.006m after adding that the team added more downforce to their car.
Third fastest, Pascal Wehrlein, was a late call up for Mercedes on Wednesday morning but managed to record valuable data for the Championship leaders as he went around the track for a total of 133 laps.
Haas driver Esteban Gutierrez did impressively to lap a time quicker than Renault driver Kevin Magnussen, Toro Rosso's Daniil Kvyat and Williams driver Felipe Massa.
Kvyat, though, was involved in a red flag incident when he suffered an engine failure between Turn 4 and 5 and with 45 minutes still left until the chequered flag was waved had to have his session cut short.
1. M. Verstappen Red Bull 1:23.267m laps 118
2. S. Vandoorne McLaren 1:24.006m laps 108
3. P. Wehrlein Mercedes 1:24.145m laps 133
4. E. Gutiérrez Haas 1:24.592m laps 105
5. A. Fuoco Ferrari 1:24.720m laps 118
6. D. Kvyat Toro Rosso 1:24.737m laps 116
7. A. Celis Jr Force India 1:25.016m laps 103
8. K. Magnussen Renault Sport 1:25.133m laps 122
9. F. Massa Williams 1:27.167m laps 94
10. J. King Manor 1:27.61m5 laps 91