Lariche sets the pace in Valencia
It was Jack Clarke that led the field initially in the 30 minute session, the Briton over a second clear of the rest of the field until his time was surpassed by Austria's Philipp Eng.
The pair briefly traded times, before Eng managed to regain his advantage halfway through free practice and looked set to end the session at the top of the timesheets until a storming lap catapulted Lariche up the field into first place.
Today marks Lariche's best performance in an F2 free practice session, although the Frenchman has good knowledge and experience of Valencia, as he scored his first car victory at the circuit in the 2008 Formula Renault West European Cup.
Behind Lariche and Eng, Clarke secured a solid third place with Kazim Vasiliauskas in fourth position – the Lithuanian edging out Russia's Sergey Afanasiev by just one thousandth of a second.
Nicola De Marco finished sixth fastest, ahead of Kelvin Snoeks in seventh, whilst Will Bratt was eighth.
Mihai Marinescu secured ninth quickest at the checkered flag, with Belgium's Benjamin Bailly rounding out the top ten.
In the championship fight, Dean Stoneman fired the opening salvo as the Briton ended free practice one in eleventh, ahead of title rival Jolyon Palmer in fourteenth – although the pair were separated by just three tenths of a second.
Results, Top-10:
1. Benjamin Lariche, 1:28.022s
2. Philipp Eng, +0.149s
3. Jack Clarke, +0.238s
4. Kazim Vasiliauskas, +0.778s
5. Sergey Afanasiev, +0.779s
6. Nicola De Marco, +0.871s
7. Kelvin Snoeks, +0.943s
8. Will Bratt, +0.1.035s
9. Mihai Marinescu, +1.040s
10. Benjamin Bailly, +1.083s