The three-time world champion Muller emerged again as the fastest of the field, just like in the earlier session. Muller improved consistently throughout the 30 minutes, from 1:46.125 he had clocked in the early stages to 1:44.991, smashing the WTCC lap record for the Moulay el Hassan circuit, 1:45.753 set by Alain Menu in 2012.
Chilton posted the second fastest lap of 1:45.050 just before the end of the session, while bamboo-engineering’s Alex MacDowall moved up to third (and best of the Yokohama Trophy) with the time of 1:45.150.
Once again the Honda drivers were the best of the rest, with Tiago Monteiro in fourth (1:45.280) and Gabriele Tarquini in fifth (1:45.304). Two other Chevrolet cars ranked sixth and seventh: Michel Nykjær’s (1:45.429) and James Nash’s (1:45.925).
Pepe Oriola topped the SEAT patrol in eighth (1:46.023), with James Thompson’s LADA in ninth (1:46.186) and Tom Coronel’s BMW completing the top ten (1:46.271).
The qualifying session will start at 15.30 local time.
Free Practice One report
WTCC competitors opened hostilities at Marrakech after Friday's rain storms put paid to all track activities, including the 30-minute test session for touring cars.
Drivers were very cautious in the early stages, testing the track's grip and new kerbs. But as the session progressed, they significantly increased their pace.
The Chevrolet Cruze and Honda Civic cars set the benchmark times, filling the four top spots on the timesheet.
Yvan Muller emerged as the fastest with a lap of 1:46.095 posted at the end of the session that was enough to beat Gabriele Tarquini's 1:46.125 by three hundredths of a second.
Muller's team-mate Tom Chilton, who had led for a while, ranked in third with a lap of 1:46.168, while Norbert Michelisz and the Zengö Motorsport Honda set the fourth fastest time of 1:46.601.
James Thompson placed his LADA Granta in a promising fifth position with a lap of 1:46.702, ahead of Tom Coronel's BMW 320 TC (1:46.835) and Michel Nykjær's Chevrolet (1:46.975) that topped the Yokohama Trophy.
Alex MacDowall (1:46.995), Tiago Monteiro (1:47.039) and Fernando Monje (1:47.347) - fastest of the SEAT drivers - rounded off the top 10.
Moroccan driver Mehdi Bennani was classified 19th and received a warning for repeatedly running off the track.