Cassidy is a master at picking exactly the right moment to pounce and make use of Formula E's two 50kW, all-wheel drive ATTACK MODE power boosts - and the 2026 Hankook Mexico City E-Prix was just the latest example of many in the GEN3 era.
The New Zealander brought his Citroen home first having sliced through the pack for his fourth win in five races - and the French automaker's first in Formula E - heading Mortara under severe pressure with the Mahindra driver leaving his ATTACK MODE deployment latest.
Cassidy did hold on though for more silverware after his P3 in the Sao Paulo season-opener, with Mortara's mirrors full of reigning champion Rowland through the sweeping final turn as the top five crossed the line within a second of one-another.
Taylor Barnard had started best, pressuring polesitter Sebastien Buemi (Envision Racing) into a mistake on the defensive at Turn 1. The young Brit led on Lap 1 as he chased the accolade of becoming the series' youngest-ever winner but was squeezed down the top six early on - winding up just about there come the chequered flag with a creditable fourth as he made it by Dennis right at the line.
Dennis himself finished fifth, ahead of Porsche's Pascal Wehrlein.
Pepe Marti (CUPRA KIRO) overcame a 60-place penalty and a Stop/Go incurred for repairs following his heavy Sao Paulo shunt to secure maiden points with a superb seventh ahead of Jean-Eric Vergne in the other Citroen, Nico Mueller (Porsche) and Norman Nato (Nissan).
All that saw Cassidy top the Drivers' table on 40 points to Dennis' 36 and Rowland on 34. Citroen head Andretti in the Teams' running 44 to 36 points. In the Manufacturers' World Championship, Stellantis have a seven point lead on Porsche.
As it happened...
Barnard started well and forced Buemi into defensive manoeuvres in order to keep a hold of P1. The Swiss looked to have done just that but outbraked himself into Turn 1, gifting the DS PENSKE driver the lead with Mortara and Mueller following by - Envision's Buemi eventually finding himself all the way down the order in 18th.
Wehrlein, down in P8, was first to jump for his initial of two mandatory 50kW all-wheel drive ATTACK MODE boosts. Four minutes for the Porsche driver, to start.
Meanwhile, on Lap 5, Mortara put the squeeze on Barnard for the lead into Turn 1, with Mueller able to follow. Wehrlein used his boost to make it by too, before taking teammate Mueller at the hairpin a couple of corners later - and the race lead into the Foro Sol.
Wehrlein led Mortara, Mueller, Dennis, Barnard, Guenther, Evans, Ticktum, Rowland and da Costa on Lap 6.
Da Costa and Maloney, 10th and 17th respectively, were next to take ATTACK on Lap 8 - the rest of the pack still held on. Meanwhile, Mueller slipped by Mortara for second into Turn 1 on Lap 9 and dispatched his teammate for P1 at the hairpin - Porsche playing the team game at the site of their first win - and one-two - back in Season 8.
Lap 11 and the pace began to pick up. Jake Dennis, Sao Paulo's winner, sat seventh with 0.5% energy in-hand on the rest of the top 10. Into Turn 1 on Lap 12, da Costa was squeezed from fourth to sixth having made up good ground from the cusp of the top 10 under ATTACK MODE.
Mortara hit the front again, with Mueller, Ticktum, Wehrlein, Barnard, da Costa, Dennis, Guenther, Evans and Rowland the top 10 - and ominously, four Porsche-powered cars in the top five positions.
The scrap on the edge of the points-paying positions lit up at the half-way stage as impatience looked to be building. Three-wide won't work all that often through the hairpin... On Lap 17 it was Oliver Rowland in the Nissan looking best placed on energy - 2-4% up on the rest as he went for his first ATTACK MODE activation.
Bad timing, though. A Full Course Yellow was required with Nyck de Vries Mahindra needing recovery - leaving Rowland's ATTACK MODE ticking to zero under caution, as Jaguar's da Costa avoided Barnard and swerved in-front of the Brit and onto the grass at the hairpin.
The race was back Green on Lap 22 with Mueller, Mortara, Wehrlein, Barnard, Dennis, Evans, Ticktum, da Costa and Rowland the top 10.
Several drivers came to blows at the hairpin as the field squeezed. Vergne, da Costa, and Guenther looked to be the ones most entangled, on Lap 26.
With many yet to take a single ATTACK MODE at the sharp end, Evans blinked first and quickly sliced his way to the head of the pack over the course of Lap 27 - beyond prior leader Mueller who was way too late on the brakes on the defensive at the hairpin.
Mortara, Cassidy and Mueller then followed with their 50kW boosts. But, as Albie Lau - former McLaren engineer - said on Broadcast, it was Cassidy who'd timed it best with energy in-hand and an overlap on ATTACK to hit the front on Lap 30.
Dennis was next to make moves, on Lap 32. He was told he had a lap's energy to the good on the lead few by his engineer and was able to make it as far as third - not quite by Mortara whose elbows were firmly out in defence, allowing Cassidy to scamper 1.3 seconds clear.
From there, it looked Cassidy's to lose - the Kiwi having gained 12 spots from his grid slot. Mortara was his closest competition with two minutes more ATTACK MODE to use to hunt the Citroen driver down.
With the top 10 all in ATTACK, reigning champion Rowland made it by Mueller and Dennis in one swoop for third at Turn 1 on Lap 35 only for Dennis to return the favour half a lap later.
The whole top five were within half a second through the stadiujm on Lap 36 - Rowland squeezed back by Dennis for that final podium spot and with Mortara's ATTACK dwindling, he couldn't quite make it by Cassidy for the lead. Some defensive drive for one of Formula E's masters in this GEN3 era.
Cassidy held on in fine style to lead Mortara and Rowland home for French giant Citroen's first Formula E victory in just their second outing.
Find out more
UNMISSABLE: Watch the brand-new season of 'Driver' on Amazon Prime
CALENDAR: Here's every race set for the 2025/26 Formula E season
FOLLOW: Download the Formula E App on iOS or Android
TICKETS: Secure your grandstand seats and buy Formula E race tickets
HIGHLIGHTS: Catch up with every race from Formula E IN FULL
HOSPITALITY: Experience Formula E and world-class motorsport as a VIP