The Swiss pilot, who started from pole position after winning Saturday’s Qualification Race, led every lap on the iconic Guia Circuit.

Behind the Mercedes-AMG Team Landorf-run Marciello, Edoardo Mortara took second for Audi Sport Asia Team Absolute with ROWE Racing BMW driver Augusto Farfus fighting back from sixth place to complete the podium as five manufacturers filled the top six positions.

Ye Hongli from China was the leading Silver-ranked driver in 10th overall for the Porsche-powered R&B Racing squad.

Marciello made the perfect rolling start to lead Maro Engel (Mercedes-AMG Team Craft-Bamboo Racing) through the first corner as Farfus slipped from fourth to sixth on the charge towards Lisboa Bend.

Although Engel closed to within 0.846s of Marciello after five laps, the slender gap was up to 0.930s when the safety car was deployed after David Weian Chen crashed his Harmony Racing Ferrari at Lisboa on lap eight.

Racing resumed on lap 10 with Marciello already pulling clear after Engel slowed with a reported gear shift issue. Due to regulations preventing overtaking before the start/finish line, the chasing pack lost ground to Marciello, whose lead had increased to 2.798s.

“It was an incredible race,” Marciello said. “In Macau it’s never easy, a mistake is always around the corner but I’m happy to finish my AMG life in this fashion. Maro was always close, so it wasn’t under control, but when I saw a big gap after the restart I thought I made a mistake and went too early! 

“It was a bit hotter than other days, but we’re used to longer races so tyre degradation wasn’t critical.”

Mortara said: “My race was an intense one from the start to the end. For some reason we were missing some acceleration and top speed than yesterday, so I had to push even harder in the mountain section, sliding around and touching the walls. I don’t even know how we managed to finish where we finished.

“I guess Maro had a problem. The move wasn’t great but it is what it is. In all honesty, we wouldn’t have been able to challenge.”

Having challenged Mortara for third in the early stages, Sheldon van der Linde’s tenure of the final podium spot, after Engel slowed, lasted barely a lap when the Team WRT driver was forced to stop to change a tyre that had been damaged by debris on track.

The South African’s misfortune let in Farfus for third after the Brazilian, who started fourth, came back from sixth having been baulked at the initial rolling start.

“After P8 in qualifying I thought it’s going to be a difficult one,” said Farfus. “I was blocked at the start. I managed to keep the car on track but I lost the momentum.

“It’s a place where you need to be lucky. I’m sorry for Sheldon. He showed incredible speed as a rookie. P3 is the maximum we could have done and a good way to finish the season.

“Macau is probably one of the highlights of the season. This year was special. The level was outstanding – the best GT3 drivers on the planet.”

Daniel Serra (Harmony Racing Ferrari) was ahead of his countryman prior to the safety car period but Farfus moved in front as racing resumed, leaving Macau rookie Serra to take fourth ahead of Mercedes-AMG Team Craft-Bamboo Racing’s Daniel Juncadella.

TORO Racing’s Laurens Vanthoor finished sixth as Christopher Haase (Audi Sport Asia Team Absolute) profited from a collision between Porsche drivers Earl Bamber (D2 Racing Team) and Kévin Estre (HebAuto Racing) at Lisboa on lap eight. Top Gold-category driver Alessio Picariello finished ninth ahead of Bamer and Hongli as Estre slipped down the order.

“The top 10 was more or less where our target is,” said Hongli. “Everything happened to me this weekend: overtaking, being overtaken, penalties. It’s a great experience. I’ve been to Macau before but this weekend was different. You couldn’t be conservative, you had to give it everything. It was great experience. We’ll be back.”

After crashing heavily in the Qualification Race, Adderly Fong was a non-starter in the FIA GT World Cup finale due to his Uno Racing Team Audi being damaged beyond immediate repair.

Re-watch the action on the FIA’s YouTube channel. Click HERE for all the results from the FIA GT World Cup.