Thierry Bollore, a 55-year-old father of five, has been declared deputy CEO to ensure day-to-day management following Ghosn's stunning arrest in Tokyo on charges of under-reporting his pay at Nissan.
Before his temporary elevation to the top of Renault, Bollore was the French car giant's Chief Operating Officer, a position he was promoted to in February in a move widely seen at the time as Ghosn anointing his successor.
In many ways the two men began with similar career trajectories. Like Ghosn, Bollore was first spotted as a rising talent at Michelin before he switched to a car manufacturer and made his way into the top ranks.
But those who have worked with him paint a somewhat softer portrait than Ghosn, who built a reputation -- and enemies -- as a maverick turnaround specialist who blew a gale through a musty corporate world, especially in Asia.
"(He's) very rigorous, very serious, but at the same time warm. He has calm, analytical qualities and he's level-headed," a senior person in the auto sector who worked with Bollore told AFP.
"I think that his knowledge of Asia and his skills in relationships with the Japanese will give him an advantage in the succession," added the former colleague, who said he appreciated Bollore's "integrity and loyalty".
Business development in China is a major priority for Renault as well as the complex Franco-Japanese coalition between Renault, Nissan and Mitsubishi.
Resentment has long been brewing in Japan over the structure of the alliance, which some say gives French carmaker Renault an undue share of the Japanese company's profits.
Renault currently owns 43 per cent of Nissan, while Nissan only owns 15 per cent of Renault.
A Financial Times report said Ghosn has been working on a merger of the two carmakers that Nissan opposed because it could relegate the Japanese company to a secondary role.
Bollore has plenty of Asia experience to draw on.
With Michelin, he held senior posts in the late 1990s in Japan and Thailand. He later joined auto-parts giant Faurecia, spending much time in China in the early 2000s, before moving to Europe and South Africa.
He joined Renault in 2012, first as executive vice president for manufacturing and supply chain and then as Chief Competitive Officer until his elevation to Ghosn's de facto deputy in February.
A keen sailor, he was viewed at Renault as someone who upped the competitiveness of the company's factories as well as embracing digital transformations.
"He's someone who is open, poised, who listens but at the same time knows when to take a position," Franck Daout, a union leader who represents some Renault workers, said earlier this year.
Thierry Bollore, 55, has been declared deputy CEO to ensure day-to-day management