Alonso jumped from eighth to third in a wet start at Marina Bay but was the innocent victim as Red Bull's Max Verstappen and the Ferrari drivers clashed on the run to Turn 1.

Sebastian Vettel moved over on Verstappen, after a slow getaway, while Räikkönen shot up the inside, and as they bunched together, Verstappen and Räikkönen touched.

Räikkönen, having been pitched into Vettel, then slid out-of-control towards Turn 1, where he made secondary contact with Verstappen, who then thumped Alonso.

Alonso's car was significantly damaged and, despite his best efforts to continue in the race, the team called him back to the pits to retire after a handful of laps.

Honda feared that Alonso, on his ninth Turbocharger and MGU-H, seventh Internal Combustion Engine and MGU-K, sixth Energy Store and fifth Control Electronics, may have needed new components.

But following checks at its Sakura headquarters, the Japanese manufacturer has confirmed that Alonso's power unit can be used again at this weekend's Malaysian Grand Prix.

"We were concerned that it may have been irreparably damaged, but fortunately after a thorough check back at the factory we can confirm it is okay to be re-used," said Honda F1 chief Yusuke Hasegawa.

Alonso himself is hoping to make up for the disappointment of his Singapore retirement.

"After Singapore, I'm already eager to get back into the car and hopefully make it further than the first corner in Malaysia!" Alonso said.

"Of course, what happened was disappointing and it's difficult to hide your frustration when you're the victim of someone else's incident.

"I felt we had the potential to be really competitive – one of our only opportunities of the year – and it's a shame we couldn't bring home the points to prove it, but these things happen.

"The conditions in Malaysia will be very similar – hot, humid and challenging for the drivers and the car.

"The configuration will work less in our favour, but of course we will still fight for everything.

"There are six races left and we are still putting all our energy in finishing every race in the best possible position we can."

Alonso and team-mate Stoffel Vandoorne ran Honda's Spec 3.7 power unit in Singapore.