Rowland started eighth and came to the fore late on as the ATTACK MODE activations shook out - with the top 10 shuffling and squabbling relentlessly for position throughout the opening half of the race.
The Nissan driver had been strong managing his energy, navigated the pack and picked his way through to the lead down at the Nouvelle Chicane on Lap 23 of 28 - classic Rowland and a second win in two years in Monte Carlo for the Brit.
RESULTS: The 2026 Monaco E-Prix Round 10
A couple of Full Course Yellows were thrown into the mix for Rowland to deal with after some overexhuberant overtaking manoeuvres down the field but the Nissan driver kept cool to cross the line first.
He headed home Edoardo Mortara (Mahindra Racing) on-track though a 10-second time penalty for the Swiss saw Drugovich take P2 for his best Formula E race finish - firmly putting to bed the Brazilian's struggles in Berlin.
Da Costa led late on and wound up third to recover from his drama in Round 9; the Portuguese rounding just ahead of Jaguar teammate Mitch Evans after being spun out on Lap 1.
Mortara secured fifth with his penalty - for contact with da Costa on the opening lap - applied with Jake Dennis (Andretti) completing the top six.
Despite a double pole in the Principality, CUPRA KIRO's Dan Ticktum couldn't convert to points - a late penalty leaving him down the order in 14th after opting for ATTACK towards the race's end.
Evans took the Drivers' points advantage after Round 9 and leaves Monaco on top ahead of Rowland. Jaguar head Porsche in the Teams' and Porsche lead Jaguar in the Manufacturers table.
Formula E returns to Sanya after a seven-season hiatus next for Round 11 on 20 June.
As it happened...
The pair that ended Round 9 in contact led the pack away with double Monaco polesitter Ticktum heading Jaguar's da Costa through St Devote.
Vergne, meanwhile, made a move for third at the Nouvelle Chicane with da Costa spinning out of second spot in contact with Mortara and all the way down to P15 at the same spot - no luck for the Jaguar driver.
Over the line on Lap 2, Mortara swept by Ticktum for the race lead with Citroen's Vergne following. The Mahindra driver flew to a two-second lead on Vergne behind with Mortara looking to make the pace in his car - as shown by teammate de Vries' Round 9 win on Saturday - count.
It was short lived for Mortara, though, with the stewards slapping him with a 10-second time penalty for that contact on Lap 1.
Nico Mueller in the Porsche was the first to jump for the initial of his two 50kW, all-wheel drive ATTACK MODE boosts on Lap 4. He made use to fire to the provisional lead.
Mueller led Mortara, Ticktum, Vergne, Rowland, Evans, Drugovich, Evans - in ATTACK - Barnard, Marti and Dennis were the top 10 on Lap 10. Jaguar's Evans used six minutes of ATTACK to slice to the race lead at Mirabeau on Lap 11 - some move from the Kiwi at the same spot as his famous overtake in Season 7.
The Andrettis were next to move for ATTACK and clambered into the top six. Vergne took his second trip through the activation zone on Lap 12 to match the yellow cars ahead up.
Mortara barged by Mueller at Turn 1 on Lap 14, with Drugovich able to follow and leapfrog the pair of them up the hill to steal P2. Ticktum finally jumped for his first ATTACK MODE on Lap 15 - the CUPRA KIRO driver down the order in P8 at the time.
The polesitter was able to force the issue to climb to an eventual second as the group ahead fought between themselves - sweeping by net leader Evans at Tabac on Lap 17 with P1 Mortara to serve his time penalty post-race.
Pepe Marti (CUPRA KIRO) and Nick Cassidy (Citroen Racing) came together at Rascasse on Lap 19 - Cassidy managing to reverse out of the scene of the accident while Marti's stuck car demanded a Full Course Yellow for it to be cleared.
Da Costa had hit the front under ATTACK in the meantime, with Mortara, Ticktum, Drugovich, Evans, Rowland, Barnard, Dennis, Wehrlein and Guenther the top 10 - though Mortara and Barnard were set to tumble with their time penalties applied.
Once clear, da Costa was able to dance to P1, a five-second lead on P3, effectively, and take ATTACK number two on Lap 20.
The lead group had all taken or were in their final ATTACK MODE with Evans and Ticktum fifth and sixth biding their time and waiting to pick their moment. Up the hill on Lap 23, Mortara and Rowland bypassed da Costa with Drugovich, Evans, Barnard, Dennis, Guenther, Ticktum and Mueller the top 10.
Rowland made a move for P1 at the chicane that same lap and looked to be in a good spot on energy, and with no driver behind having an overlap in ATTACK.
Barnard's busy race came to an end in the wall at Portier after an overambitious move on da Costa went awry on Lap 26. Another brief Full Course Yellow for Rowland to navigate but the Nissan driver was able to convert from there to lead the field home.
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