Sesko rounded goalkeeper Stas Pokatilov to convert on the stroke of half-time, completing a dominant opening 45 minutes for United in their first Champions League appearance in three years.
Matheus Cunha had opened the scoring earlier in the half, with Bruno Fernandes doubling the advantage shortly before Sesko added a third, and Lisandro Martinez rounded off the rout with the only goal of the second period.
Speaking to TNT Sports on the pitch afterwards, alongside team-mate Patrick Dorgu, Sesko reflected on what the emphatic scoreline could do for the squad's momentum.
"It was perfect for everyone, especially our fans," he said. "It means a lot to them, especially to see so many goals. I think it was great for us in general to give us more motivation for the upcoming games."
The goal was Sesko's second in as many appearances, having netted his first of the season off the bench in United's previous outing at Everton. Describing his third-goal finish, the forward explained: "I saw him [Pokatilov] rushing out and I was quite overjoyed to take the ball away from him to make the goal a little bit easier. Of course, I'm happy."
Sesko was one of four different United scorers on the night, a spread he views as a significant asset for Michael Carrick's side as they build depth across the campaign.
"I think it's important, especially when everyone can score a goal, it's very important," he said. "I hope for many games like that."
Sesko joined Manchester United from RB Leipzig for an initial £66.3m, rising to around £74m with add-ons, in a deal completed last August that saw him beat Newcastle United to the move. The Slovenian has faced competition for a starting berth from Cunha and Bryan Mbeumo since his arrival, but Thursday's outing offered a reminder of the qualities that persuaded United to make him one of their marquee summer signings.
The result also moved United into a strong early position in the Champions League's new league-phase format, with Atletico Madrid awaiting in October as their next European assignment. Attention now turns to Sunday's Manchester derby against City at Old Trafford, with United hoping to carry their European form into the Premier League.
Sesko believes the manner of the win over Sabah leaves the squad well placed for the challenge.
"Definitely, the confidence boost here is definitely big," he added. "Now, it's important to recover very well and obviously focus on the derby."