Ulster failed to build on a lightning quick start but still managed to see off Aironi at Ravenhill, outscoring the Italians by three tries to one.
Home props Tom Court and Declan Fitzpatrick helped themselves to tries and teenage winger Craig Gilroy also crossed for his seventh try in as many games.
That was the bulk of the scoring for Ulster who were 15-0 in front after just 14 minutes. Aironi came back into contention with a try from full-back James Marshall and five points from the boot of out-half Riccardo Bocchino.
But despite losing stand-in captain Johann Muller to the sin-bin, Ulster stretched their lead with a penalty from Ruan Pienaar, who donned the number 10 jersey, and a 71st minute try from Fitzpatrick clinched the win.
It was Ulster's third Magners League victory in quick succession and has them right in the hunt in terms of reaching the play-offs.
Bottom side Aironi can be pleased with their level of performance, with their pack's physicality helping them recover from a sloppy start.
They were lining up behind their posts in the third minute after Court drove over for his try. Ulster, who were impressive winners over Cardiff last time out, kicked a penalty to touch and after Muller won the lineout, the Ireland front rower pounced to score.
Pienaar's conversion attempt bounced back off the post but he was back on target when converting Gilroy's try, four minutes later.
Paddy Wallace's inside pass set the wheels in motion as Andrew Trimble took the ball and the space was created for Chris Henry to send Gilroy over on the left.
Pienaar's successful conversion was followed by a penalty and the 7,700 must have sensed more scores. However, errors then began to creep into Ulster's game and they lost the early momentum.
Aironi got on the scoreboard with a penalty from Bocchino, after Court was pinged for not rolling away. Pienaar missed a chance to reply, flicking a penalty effort off the post and wide.
Rowland Philips' side struck for a well-worked try before half-time. Big back rower Nick Williams charged forward and the ball was switched to the blindside where Marshall exposed some poor defending to score under the posts.
Bocchino followed up with the conversion to leave just five points between the sides at the break – 15-10.
Pienaar had to react sharply to deny Danwel Demas after the winger had intercepted a pass. Aironi kept the pressure on and won a series of penalties which ultimately led to Muller's sin-binning.
14-man Ulster managed to hold out and even added timely penalty from Pienaar before the big South African lock returned to the pitch.
A half-break from Wallace, who switched to out-half, opened things up for Ulster in the closing stages and Fitzpatrick got over following confirmation from television match official Marshall Kilgore.
In the final minutes, Aironi had a great chance to register their sixth losing bonus point of the campaign. But replacement hooker Tommaso d'Apice ruined it when he threw a forward pass to Kaine Robertson who looked poised to score.