A raucous crowd of 36,000 witnessed the greatest escape act in Formula E history on Saturday at the Julius Baer Mexico City ePrix.

Never before had a driver won from so far back on the grid. Never before had a driver had to change a rear wing and gone on to win.

Yet Brazil's Lucas di Grassi, who started 18th, accomplished the incredible feat - aided in no small part by some inspired calls by his ABT Schaeffler Audi Sport pit crew.

It was a bold decision to pit on lap 17 of the 45-lap race, but after taking advantage of two of the three Qualcomm Safety Car periods, di Grassi found himself with a 30-second lead and managed to keep his rivals at bay with superb energy-efficient driving.

"What an incredible change of fate, but actually that's what Formula E represents ... there are so many ups and downs," said di Grassi.

"I managed to open a gap and keep on just using regeneration, trying to be as energy efficient as possible and focusing on my race as much as possible until the last corner. Then I just celebrated like crazy.

"For me it was one of the best races of my life, in terms of how I drove, how energy efficient I had to be, so I'm very pleased."

The victory helped di Grassi end Sebastien Buemi's three-race winning streak while whittling the Swiss driver's championship lead down to just five points as the series heads to Europe.

Jean-Eric Vergne finished runner-up for China's Techcheetah team, bringing the new entry its second straight podium finish after Buenos Aires in February.

The Frenchman actually had a good chance to win on Saturday when di Grassi's lead evaporated when the safety car was deployed for the final time. Vergne took over third and had much more energy left than di Grassi and Jerome D'Ambrosio, who was running second.

But D'Ambrosio was in no mood to give up his spot, and for lap after lap he doggedly kept Vergne at bay with some aggressive driving.

On the final lap the Techcheetah driver finally snaked his way through, and even though he managed to scythe into di Grassi's lead, he simply ran out of time.

"I have very mixed emotions. I think this race was ours - 100 percent," said Vergne.

"What D'Ambrosio did was totally unacceptable. He just doesn't know how to defend. He repeatedly crashed into me and forced me to go off the track, so I'm not a fan. He changed direction many times, so I'm very frustrated.

"But on the other hand, I'm happy that I'm here for the championship. We started very far back, but I know I'm on the right team with the right car to win the championship. I think we're coming back a little bit better and we're getting stronger as a team with every race."

Vergne's new teammate, Mexican driver Esteban Gutierrez, marked his debut for Techcheetah with a point for 10th place.

A superb drifting move around the outside into the Turn 3 right-hander took Sam Bird past D'Ambrosio and into third place on the final lap. The DS Virgin Racing driver was ecstatic to claim his second podium of the season.

The series resumes on May 13 at the most famous street racing venue of them all - Monaco.

xujingxi@chinadaily.com.cn