Rowland logged a 1m10.559s at the death of FP1, preceded by a 15-minute shakedown earlier in the day, dispatching Antonio Felix da Costa from the top of the times to draw first blood for the 2021-22 season.
Da Costa had originally been able to hold on from a late onslaught by DS Techeetah teammate Jean-Eric Vergne to cement the fastest time, but Rowland's last-minute effort left the Portuguese driver second - 0.158s off the best time.
Sam Bird set the first time unaffected by an early, performatory full-course yellow, a 1m18.635, but the times quickly tumbled as his Jaguar teammate Mitch Evans immediately sent the British driver down a spot and went six-tenths faster.
Bird had earlier labelled the track "horrendous", owing to a huge concentration of dust all over the road surface owing to desert sand and local construction work.
As the dust began to clear, the laptimes dropped into the 1m15s, with Pascal Wehrlein posting a 1m15.867s before the Porsche driver was dispatched by Sebastien Buemi's 1m15.622s.
De Vries then punctuated the opening 10 minutes with another full-course yellow, sliding on the dust at Turn 3 and clouting the barrier with his left-rear wheel for a dose of suspension damage.
Once running resumed after the Dutchman had retreated to an exit road, Buemi continued to wind down the times with a 1m14.023s, until two-time Formula E champion Jean-Eric Vergne set a 1m13.716s.
Evans and Wehrlein then nudged past Vergne, until Robin Frijns clocked a 1m13.411s to sit top of the times at the half-way stage.
Frijns' minute-long reign at the top of the timesheets was ended by Evans diving into the 1m12s, but the circuit continued to evolve as Stoffel Vandoorne broke into the 1m11s - although was overhauled in short order by Techeetah duo Antonio Felix da Costa and Vergne - the latter posting a 1m11.019s.
Da Costa hit back with a 1m10.717s and looked to end Thursday's running with bragging rights after Vergne's purple opening pair of sectors came to nothing with a late slide, but Rowland's final lap then deposed the 2019-20 champion.
Jake Dennis was third with his own late effort, setting the quickest finals sector to best Vergne, as Evans was fifth fastest.
2020-21 runner-up Edoardo Mortara was sixth fastest, with Wehrlein seventh - but under investigation for speeding under the full-course yellow.
Buemi was eighth ahead of Venturi's new charger Lucas di Grassi, as Nick Cassidy completed the top 10.
Dan Ticktum was the best of the rookies, finishing 13th fastest - nearly a full second ahead of NIO 333 teammate Oliver Turvey.
Diriyah E-Prix - First practice results:
| Cla | # | Driver | Team | Time | Gap |
|---|---|---|---|---|---|
| 1 | 30 |  Oliver Rowland |  Mahindra Racing | 1'10.559 | |
| 2 | 13 |  Antonio Felix da Costa |  Techeetah | 1'10.717 | 0.158 |
| 3 | 27 | Jake Dennis | Avalanche Andretti Formula E | 1'10.739 | 0.180 |
| 4 | 25 |  Jean-Eric Vergne | Techeetah | 1'10.744 | 0.185 |
| 5 | 9 |  Mitch Evans | Jaguar Racing | 1'11.064 | 0.505 |
| 6 | 48 |  Edoardo Mortara |  Venturi | 1'11.080 | 0.521 |
| 7 | 94 |  Pascal Wehrlein | Porsche Team | 1'11.139 | 0.580 |
| 8 | 23 | Sébastien Buemi | DAMS | 1'11.199 | 0.640 |
| 9 | 11 |  Lucas di Grassi | Venturi | 1'11.233 | 0.674 |
| 10 | 37 | Nick Cassidy | Virgin Racing | 1'11.329 | 0.770 |
| 11 | 36 | Andre Lotterer | Porsche Team | 1'11.400 | 0.841 |
| 12 | 29 | Alexander Sims | Mahindra Racing | 1'11.461 | 0.902 |
| 13 | 33 | Dan Ticktum | NIO Formula E Team | 1'11.478 | 0.919 |
| 14 | 5 |  Stoffel Vandoorne | Mercedes | 1'11.610 | 1.051 |
| 15 | 4 |  Robin Frijns | Virgin Racing | 1'11.640 | 1.081 |
| 16 | 10 | Sam Bird | Jaguar Racing | 1'11.751 | 1.192 |
| 17 | 22 | Maximilian Gunther | DAMS | 1'11.921 | 1.362 |
| 18 | 7 | Sergio Sette Camara |  Dragon Racing | 1'11.955 | 1.396 |
| 19 | 3 | Oliver Turvey | NIO Formula E Team | 1'12.361 | 1.802 |
| 20 | 99 |  Antonio Giovinazzi | Dragon Racing | 1'12.442 | 1.883 |
| 21 | 28 | Oliver Askew | Avalanche Andretti Formula E | 1'12.668 | 2.109 |
| 22 | 17 | Nyck de Vries | Mercedes | 1'40.153 | 29.594 |
| View full results | |||||
