Toyota Gazoo Racing’s Mike Conway led the opening hour of the 8 Hours of Bahrain after benefiting from a clash between front-row starters Bruno Senna and Charlie Robertson.
Conway, who started fourth on the grid, managed to slip past as Senna in the pole-sitting Rebellion Racing R13 Gibson and Robertson in the No. 5 Ginetta G60-LT-P1 AER rotated following contact.
Robertson appeared to lose the rear of his Team LNT Ginetta as the pack switched to the Turn 2 left-hand kink after the tight Turn 1 right-hander and clattered into Senna.
Both cars rotated with the Ginetta taking the most damage while Sebastien Buemi was also caught up and lost seven overall positions in his No. 8 Toyota TS050 Hybrid.
This incident scattered the LMP1 field and left the LMP2-leading United Autosports Oreca 07 Gibson of Paul di Resta in second overall as Conway sped away out front.
Second in the top LMP1 class was Team LNT’s Mike Simpson who was fifth in the outright order while Buemi and Senna were further back in the 31-car field.
It then took 25 minutes for all the LMP1 cars – except Robertson’s Ginetta which lost two laps – to overtake the LMP2 field.
Senna also caught and passed Sebastien Buemi after powering past the No. 8 Toyota, which is running with the largest Success Handicap this weekend, on the main straight.
In LMP2, di Resta consolidated his pole position to lead through the opening round of pit stops from Job van Uitert in the G-Drive Racing Aurus-badged Oreca.
Nico Lapierre was third for a time for Cool Racing but the Frenchman fell back in the opening stint as Andre Negrao, Kenta Yamashita and Anthony Davidson found ways past.
AF Corse Ferrari driver Alessandro Pier Guidi led the first stint in GTE-Pro after a first-corner shuffle led to pole man Gianmarai Bruni losing four places in his Porsche 911 RSR.
Bruni was knocked out wide when Pier Guidi locked up slightly into Turn 1 and surrendered positions to the new leader as well as Kevin Estre (Porsche), Marco Sorensen (Aston Martin) and Miguel Molina (Ferrari).
Pier Guidi had drawn out a three-second gap to Estre by the end of the first hour while Bruni was up to third having worked his way past Molina.
The Porsche driver then took another place when Sorensen brought the No. 95 Aston Martin Vantage GTE in for an early regular pit stop.
Team Project 1 controlled the opening stanza in GTE-Am as Ben Keating converted his pole position into a 15-second lead from teammate Egidio Perfetti.
Third in class behind the two Porsches was the Aston Martin of Paul Dalla Lana.