Ticktum's strong first and final sectors carried him to the top of the timesheets, initially with half a second over Jaguar's Mitch Evans.
Although Buemi and Stoffel Vandoorne filled that bracket by the close of the session, Ticktum's time handed him an ultimately unassailable advantage.
Jake Dennis was top after the opening 10 minutes of the session with a 1m11.376s, deposing last year's winner Edoardo Mortara from the top after an early shuffle of times, but Sebastien Buemi then found a tenth over the Mexico winner.
The NIO 333 pair then swept to the top on 350kW power laps; Sergio Sette Camara did a 1m11.191s, before Dan Ticktum broke the 71s barrier with a 1m10.924s to get the times closer to Thursday's evening running.
Rene Rast then jumped the pair, briefly standing atop the timing boards before Dennis' riposte of 1m10.777s returned the Andretti driver to the top - while only running at 300kW.
Next, Buemi hit the head of the timesheets with a 1m10.742s on full power, but Ticktum returned to the headlines with the first lap faster than Thursday's efforts - a 1m10.386s the reward for his efforts.
The Briton then took a hacksaw to his own benchmark and posted a 1m10.099s, throwing down the gauntlet for the other drivers to pick up as the session entered its final stages.
Vandoorne was close to topping Ticktum after beating the Londoner in the opening pair of sectors, but continual struggles to get the drive through the final pair of corners left him four tenths adrift at the close of the lap.
The same was true of Buemi, but his efforts to displace Ticktum were once again beaten by the 2018 Macau Grand Prix winner's fast final sector. The Swiss ultimately had to be content with second, 0.203s shy of Ticktum, but ahead of Evans by 0.145s.
Evans bumped Vandoorne out of third by the close of the session, ahead of Sam Bird.
Bird had headed Thursday afternoon's opening free practice session from Jean-Eric Vergne, as Jaguar had shown improved pace over Mexico.
The Briton, who has won the Diriyah E-Prix twice in his Formula E career, set the benchmark at the end of the first day with a 1m10.402s, a scant 0.084 clear of Vergne.
Pascal Wehrlein and Sette Camara were sixth and seventh, clear of Rast, while Jakes Dennis and Hughes completed the top 10 with an identical 1m10.777s.
The top 20 cars all set their best times within a second, with the two Abts falling shy of that boundary - with Robin Frijns' replacement Kelvin van der Linde 1.594s off the pace.
His teammate Nico Muller hit the Turn 16 exit wall, breaking the left rear of his Mahindra-powered Abt car to bring an end to his session after just 10 minutes of running.
Diriyah E-Prix FP2 result
