Alexander Sims took his first Formula E win in an incident-strewn second race of the season in Saudi Arabia.
When the lights had gone out to start the race, Sims had produced a ideal start to jump away from the rest of the field with Buemi initially holding on to second place while da Costa was able to get the better of di Grassi down the inside of turn 18. But in the process he made contact with Buemi's vehicle, sending him spinning into oncoming traffic.
Race 1 victor Sam Bird, who had started seventh, was tapped by Panasonic Jaguar Racing's Mitch Evans going through Turn 4, and then hit again by Mahindra Racing's Pascal Wehrlein going through Turn 5, sending the British driver's Envision Virgin Racing entry into the wall and out of the race. Evans was given a drive-through penalty for causing a collision.
However the stewards then took a hand in the proceedings, issuing a drive through penalty to da Costa for his original contact with Buemi, and a ten-second time penalty to Buemi for his ensuing unsafe rejoin.
It was a typically entertaining race for Formula E - the second contest of the weekend involved two safety cars and a full course yellow, after the field started racing again before Robin Frijns' stricken Virgin auto had been cleared from the circuit.
Despite the safety vehicle, Vergne was unable to make his way into the top ten by the chequered flag, making it a pointless first weekend in the Frenchman's 2019/20 title defence.
Sims now leads the championship, following a seventh place finish on Friday, by seven points from Stoffel Vandoorne and nine from fellow Briton Bird. But it wasn't enough: Both BMWs crossed the line in tandem as Sims clinched his first career Formula E win.
"That was pretty much a dream race", said Sims, who started the race from pole position - his third in a row. "Crossing the line was an fantastic feeling - there's so many lessons we've learnt". We keep learning so many lessons and there are many more to come in the near future. "Also a one-two for the team is a fantastic result and big congratulations to my teammate".
Since its inaugural season in 2014, Formula E has undergone a multitude of changes, from technology to personnel.