Stoffel Vandoorne's third-place finish for Mercedes on its Formula E debut was "far more" than the team expected, according to programme chief Ian James.

Mercedes has joined the Formula E grid as a fully-fledged manufacturer for Season 6, partnering Vandoorne with Formula 2 champion Nyck de Vries, with the pair qualifying second and third respectively for the season-opener in Diriyah, Saudi Arabia.

Vandoorne managed to get the jump on pole-sitter and early leader Alexander Sims in the second stint of the race, but was unable to stop Sam Bird or Andre Lotterer from passing in the closing stages, leaving him to settle for third.

De Vries finished the race sixth after losing places when going off-line for his second Attack Mode boost.

Team chief James was delighted with the result, saying it went beyond the team's expectations, but stressed it would be staying grounded.

"Finishing third and sixth in our very first race is far more than we expected and a huge reward for the whole team. The race has shown that we have achieved a certain level of consistency for our cars over the last months," James said.

"But as you could see throughout, there is strong competition between all of the teams. Going at a fast pace, the field was really close from start to finish.

"Still, I am certain that we will see a very different race tomorrow. It will be a fresh start for everyone. We need to stay focused and not be distracted by today's rather very pleasing result."

Vandoorne hailed his podium finish as an "incredible achievement" for the Mercedes team.

"We've had a very busy time preparing for the season, and getting everything right was not always easy. Starting the season with a podium finish is just fantastic for all of us," Vandoorne said.

"Since I've already spent a year contesting Formula E, I too was able to do my bit and am very proud of all the people involved. Of course, the good qualifying was a great way to start our first race weekend. We may have had a small advantage in that we were in one of the groups that went out later, but we still had to deliver, and we succeeded.

"It was not a perfect race, but that's good. There's still much that we can improve, but this was a better result than we expected on our debut."