Arsenal began life after Jonas Eidevall by getting their Women's Champions League campaign back on track with a 4-1 victory over Valerenga.
Eidevall resigned as the Gunners' head coach on Tuesday after three years in charge, following a poor start to the 2024-25 season.
Nevertheless, with interim boss Renee Slegers taking over, Arsenal bounced back on Wednesday with a comfortable win at Emirates Stadium.
Just two minutes had elapsed when Emily Fox slotted home the opener, while Alessio Russo was denied by the offside flag soon after.
The hosts made it 2-0 on 29 minutes when Mariona Caldentey powered through the middle of the park before finding Beth Mead, whose deflected shot was parried by the goalkeeper, and subsequently tucked away by Caitlin Foord at the far post.
However, a lapse in concentration allowed Valerenga to pull a goal back before the break, Olaug Tvedten halving the deficit after pouncing on Laia Codina's mistake.
The Gunners gave themselves breathing space five minutes from time, as a neat move culminated in Stina Blackstenius crossing for Caldentey, who fired into the roof of the net.
Caldentey was involved again as Arsenal added further gloss to the scoreline in stoppage time, her precise pass releasing Russo to slot home through the legs of Valerenga goalkeeper Tove Enblom, with the Gunners comfortably ensuring their run of never losing their opening two matches of a Champions League campaign continued.
Meanwhile, reigning champions Barcelona bounced back from their matchday one defeat to Manchester City with an emphatic 9-0 rout of Hammarby, in their first meeting in the competition with the Swedish side.
Barca had won all nine of their previous home group-stage matches in the competition, and eased into a 3-0 half-time lead with Caroline Hansen, Claudia Pina and Alexia Putellas on target.
Pina and Hansen doubled up after the break, while there were further strikes from Mapi Leon, Ewa Pajor and Esmee Brugts, as well as a last-minute Fridolina Rolfo penalty.
Barca finished with 5.84 expected goals (xG) to Hammarby's 0.44, and 33 shots to seven.