The Mercedes-AMG Team Landgraf driver capitalised on his pole position to lead the field away from the rolling start and remained in front thereafter for first place on the iconic 6.12-kilometre Guia Circuit.

In a race interrupted by two safety car periods and a red flag, Maro Engel made it a Mercedes-AMG GT3 one-two in second place, 1.172s behind Marciello, as Edoardo Mortara completed the top three aboard his Audi Sport Asia Team Absolute Audi R8 LMS GT3 Evo 2.

“With two safety car restarts it’s never easy here with those long straights, you can always lose the positions, but no one took a big risk to overtake because the big [race] is tomorrow. It was important to finish the race in front,” said Marciello, who was presented with the Pirelli Pole Position Award by the company’s Circuit Activity Manager, Matteo Braga, for securing top spot on the grid for Sunday’s main event, the sixth FIA GT World Cup.

Of the prospect of winning again on Sunday and the need to adapt his car’s set-up to what should be cooler track and ambient temperatures, Marciello said: “It’s the same for everyone. If it’s different for me it’s also different for the others, we’ll have to adapt.”

Engel’s getaway from the rolling start would prove decisive in the battle for the runner-up spot behind Marciello. The German, driving for Mercedes-AMG Team Craft-Bamboo Racing, was able to carry more momentum through the first corner and then hold his nerve to edge ahead as the field rushed through the high-speed Mandarin Oriental Bend.

"Trying to gain positions is never easy here, but I had a good run on the way to Turn 2, I was slightly ahead, and luckily, I could go around Edo [Mortara] there. It’s one of those very high-speed corners and very challenging," said the Mercedes-AMG works driver.

"I was quite close [to Raffaele Marciello] after the restarts but it’s obviously quite a risk at this stage. I think securing 1-2 was the priority. We’ll try to improve overnight and will see what opportunities we’ll have tomorrow," he added when asked how he approached the race.

With Matteo Cairoli (Absolute Racing Porsche) and Thomas Preining (HubAuto Racing Porsche) both stopping with damage on the run out of San Francisco Bend, a four-lap period behind the safety car followed while the stricken cars were removed.

When racing resumed, Daniel Juncadella attempted to snatch third from Mortara at Lisboa. Although the Spaniard was slightly in front heading into the corner, his positioning on the outside meant Mortara had the advantage. With insufficient space for both cars to run side by side through the corner, Juncadella ended up nudging the tyre barrier as he conceded the place.

The Mercedes-AMG Team Craft-Bamboo Racing driver’s brief delay left Mortara still in third while Juncadella slipped back, a brush from the passing Augusto Farfus (ROWE Racing BMW) adding to his woes.

A second safety car intervention then followed after Adderly Fong crashed heavily exiting Mandarin. The Uno Racing Team lost the rear end of his Audi, hit the barriers on the outside of the flat-out turn before ricocheting across the track where heavy contact was made.

The Hong Kongese was uninjured but with debris on the track and the safety barriers significantly damaged, the race was halted to enable a full clean up and repairs to be made

When the race restarted it was effectively a two-lap sprint to the flag. Although the top-four positions remained unchanged, Sheldon van der Linde overtook fellow Macau rookie Daniel Serra for fifth heading towards Lisboa.

Laurens Vanthoor, Christophe Haase, Juncadella and Earl Bamber completed the top 10 as China’s Leo Honli Ye finished as the top Silver-ranked driver in 13th.

Once they are made final, the results of the Qualification Race will decide the grid for Sunday’s FIA GT World Cup finale. The 16-lap race is scheduled to begin at 12:05 local time (GMT +8 hours) with live coverage on the FIA’s YouTube channel. Click HERE for live timing.