Captain Kwak Tae-hwi's towering header inside the first 15 minutes set the home side on their way in front of a lively 42,153 crowd at Ulsan Munsu Stadium before Rafinha's fifth goal in five games doubled the home side's lead just after the hour mark.
And with Kim Seung-yong emphatically adding a third with 15 minutes remaining, the AFC Champions League title returned to Korean hands for a third time in four years as Ulsan completed a perfect unbeaten campaign with their ninth consecutive victory in the competition.
Looking to follow in the footsteps of 2009 champions Pohang Steelers and 2010 winners Seongnam Ilhwa Chunma, the home side took the game to Al Ahli from the first whistle and Brazilian striker Rafinha had the first shot on target after seven minutes before captain Kwak headed wide from another Ulsan corner three minutes later.
But just three minutes later the home side took a deserved lead as Kim Seung-yong's flighted free-kick caught the Al Ahli defence flat-footed and Kwak rose the highest on the edge of the six yard area to direct a glancing header into the bottom corner.
The visitors slowly came into the contest midway through the first half, but Ulsan still looked the most likely to increase their lead as Colombian midfielder Juan Estiven Velez tried his luck from long range after 25 minutes.
Al Ahli's first shot on target finally arrived after 32 minutes as Brazilian striker Victor Simoes guided a tame free-kick from the edge of the area into the grateful arms of Ulsan goalkeeper Kim Young-kwang.
Rafinha took just 19 seconds of the second half to warm the gloves of Al Ahli goalkeeper Abdullah Al Muaiouf, while at the other end Simoes fired straight at Kim Young-kwang from the edge of the area.
Ulsan continued to pose the greater attacking threat as the second half progressed and the home side were finally rewarded with a crucial second seven minutes after the hour mark as Velez's deep cross into the penalty area was headed back across the face of goal by Kim Shin-wook for Rafinha to poke home from close range despite the presence of two Al Ahli defenders.
And with 15 minutes remaining, Kim Seung-yong's empathic angled strike from inside the area rocketed into the top corner giving Al Muaiouf no chance.
Kim Seung-yong came close to a second just two minutes later before Kim Shin-wook headed onto the outside of the post with two minutes remaining before seeing a stooping stoppage time headed ruled out for offside