Iran dominated the first half and created a string of clear cut chances but failed to find a way past UAE goalkeeper Eesa Abbas until right-back Bahram Dabbagh finally broke the deadlock just before the hour mark.
Substitutes Aghaj Imamighareh and Ali Heydari wrapped up the win against a UAE side who finished the game with nine men as captain Haddaf Abdulla and Mohamed Hussain were sent off in the closing stages.
But while the 3-0 score line at MHSK Stadium seems to signify a convincing win for unbeaten Iran, who have won all five games in Uzbekistan, Doustimehr was far from happy after warning his side against complacency before the game.
"This game was not suitable for a semi-final as the players did not play as I wanted them to play. The game was preparation for the final against Japan or Korea as we knew we could beat UAE," said Doustimehr.
"We created chances in the first half, but could not score. The UAE could also have scored but we managed to score in the second half.
"We were lucky we played the UAE in the semi-final and not a stronger team. After we beat Syria the players thought it would be easy. We were lucky we did not meet a stronger team."
Omid Kharaji struck the post, Abbas saved from Mehrdad Yeganeh and Mehrgan Golbarg before captain Rayam Sadeghian wasted the best chance of the first half as he fired wide after beating the offside trap and with only the goalkeeper to beat.
But Iran stuck to their task and were finally rewarded as Dabbagh skipped past Ahmed Mohamed’s challenge and fired past Abbas.
Abbas denied Imamighareh and defender Rashid Mohamed cleared Sadeghian’s shot off the line before the second finally came through Imamighareh’s 77th minute thunderbolt.
In a frantic finish, Abdulla was dismissed in the last minute after picking up a second yellow card and Heydari tapped home the third in stoppage time before Hussain was shown a straight red card.
"In the first half they played with eight players behind the ball which was hard to break down," added Doustimehr.
"In the second half we looked at using the open space better and we were able to score."