Derek McInnes had instructed his team to deliver a controlled, professional display in Riga after a first-leg 5-0 demolition last week and he was satisfied with another simple success. Indeed, there was never any danger of a shock, as Rooney picked the hosts apart with a display of clinical finishing in the first half.
The Irishman became the first Aberdeen player to register a treble in European competition since Mark McGhee did so against Ujpest Dosza of Hungary in the 1984 European Cup-Winners Cup quarter-final.
While McInnes can now look ahead to what will be a somewhat meatier, not to mention trickier, tie against Dutch side Groningen next week, the Aberdeen manager first acknowledged his satisfaction with the performance of his side in Latvia.
"It was important we didn't give Daugava any encouragement at the start of the game," he said. "Other than a few balls over the top of us we dealt with what they had to offer. I thought the three goals were excellent and well worked - it was very clinical from Adam. They were real good finishes and two of them were top quality.
"Our approach was spot on and we asked the boys to be professional. It was a mature and competent performance. Over the two legs, they were good performances and there is a lot to be pleased about. We know there are bigger challenges ahead of us.
"I have got to be pleased with two clean sheets and coming away with no injuries in the second leg. Adam makes good runs across people and he anticipates well, especially when defenders are flat-footed. He thrives off good service and he got that."
Aberdeen made two changes from the side which demolished Daugava last week, with central defenders Ash Taylor and Andrew Considine replacing the injured Peter Pawlett and club captain Russell Anderson in the starting line-up. It proved to be a comfortable enough debut for Taylor, a former Tranmere Rovers player, who had very little to do.
The Latvians did come close to taking an unexpected lead within the opening two minutes, however, when Mantas Savanes lifted a shot over the crossbar. With one shot he offered more of a threat than his side had during 90 minutes at Pittodrie.
Normal service was soon resumed, though, and Niall McGinn came close to putting the visitors ahead when Rooney chested Barry Robson's pass into his path after 18 minutes. The Northern Irishman volleyed inches over.
Aberdeen did go in front four minutes later following a cool finish from Rooney. Jonny Hayes - restored to his favoured role on the left wing - did the groundwork by delivering a low cross and Rooney flicked the ball in with the outside of his boot to delight the 300 travelling fans.
Shay Logan nearly added to the goal he scored in the first leg when his cross from the right almost deceived goalkeeper Janis Krumins, who had to claw the ball away desperately. McGinn came close to scoring too and Logan had another effort which was just a fraction wide as their side dominated.
It was no surprise when Rooney doubled his tally and Aberdeen's advantage five minutes before the break when he turned in Logan's cross from the right with another instinctive finish. The striker duly completed his hat trick in the last minute of the first half, profiting from another delectable cross from Hayes.
Predictably, the second half resembled a glorified training session for Aberdeen with the game long since over. Jamie Langfield, the Aberdeen goalkeeper who had again been reduced to a virtual spectator, was called into action belatedly when he made a decent block from a rare Latvian attack when Edgars Karklins tested him with 20 minutes to go.
McInnes offered run-outs to young players Nicky Low and Scott Wright in the final 10 minutes, with the home side also closing the door on any more Aberdeen goals.
However, an 8-0 aggregate success was a more than satisfactory way to round off their first European tie in five years.