The Iranian champions secured victory at the Azadi Stadium with three goals in seven first-half minutes from the returning Ali Karimi, Alireza Vahedinikbakht and Mohammed Nowrouzi.
But they took their foot off the pedal after the break and allowed the United Arab Emirates league side to pull a goal back through Mishal Wahab.
"The least we could do today was to put them under pressure in the first-half and we did this and we won the match in the first 45 minutes," said the Portuguese tactician, who dedicated the victory to a young fan with a brain tumour.
"Asian Champions League matches are high quality and it's difficult for a team to play as well as we did in the first half for the whole game.
"But I expect my players to fight and pressure the opposition for the whole match."
Former Iran international Ali Karimi had an impressive first-half but was substituted by Vingada at half-time after complaining of back pain.
However, Vingada refused to put his team's lacklustre second-half display down to Karimi's absence.
"It had nothing to do with our decline. We went off the pace after we scored when Karimi was still on the pitch.
"There's no doubt we're better when Karimi's in the side because he's a special player. But we must focus on the team not one player."
Vingada's opposite number, Toni Oliveira, felt that the better team won.
"They put us under a lot of early pressure and we made a lot of mistakes which helped them win the game in seven minutes.
"But in the second half we were more organised and their pressure dropped off, allowing us to play better.
"We know how good we are and how we compare with the other teams in the group and because of this I'm happy with the players.
"We must play six matches in the group but the most important thing is to learn and enjoy the Asian Champions League.
"It's a good chance to improve and test ourselves against stronger teams so in the future we can become better."