Al Nasr, who qualified for a maiden appearance in the competition after finishing third in the UAE Pro League last season, started brightly but faded as the game progressed, although it took until the 86th minute for Correa to finally break the deadlock.
Italian striker Luca Toni had the best chance of the game in the first half for Al Nasr, but the World Cup winner was starved of service in the second period, although a heroic goalkeeping performance from Abdulla Moosa almost earned Walter Zenga's visitors a point from the Group C opener.
"We got off to a good start and I believe Sepahan deservedly snatched all three points," said Sepahan coach Zlatko Kranjcar.
"We had the game under our control from the kick-off. I knew they'd plan on defending a lot, so I sent three strikers out there on the pitch. We could have scored even more, but squandered away most of our chances.
"I appreciate the way they played, Al Nasr is a good team, in my opinion.
"Moharram Navidkia and Emad Mohammed were not in my line-up because the duo were suffering some injury problems, so they came onto the field a bit later in the game. However, they were influential for us."
With Al Nasr enjoying an encouraging start to their maiden continental appearance, the visitors had the best of the chances in the opening 45 minutes as Australia midfielder Mark Bresciano skimmed the top of the net with a free-kick midway through the first half.
And at the end of an entertaining but goalless first half, Toni should have handed Al Nasr the lead but the Italian headed wide at the back post despite ghosting in to meet an inviting free-kick unmarked.
Sepahan, though, increased the pressure after the break as Brazilian midfielder Fabio Januario drew an acrobatic save from Al Nasr goalkeeper Moosa midway through the second half.
Moosa was left rooted to the spot as midfielder Mehdi Karimian diverted a well-struck low shot from Albanian striker Xhevahir Sukaj onto the outside of the post shortly after.
Karimian again came close to a breakthrough as Moosa was called into action with just over 10 minutes remaining to push away the low skidding strike from the midfielder.
But with four minutes left to play, Sepahan finally found a way past Moosa as second-half substitute Moharram Navidkia was given too much time on the edge of the Al Nasr area and the midfielder took full advantage by slipping a pass through to the onrushing Correa and the Brazilian calmly lifted the ball over the advancing goalkeeper from just outside the six yard area.
"We did our best to get a good result and return happily from Sepahan, but we failed to do that," said Al Nasr coach Zenga.
"I congratulate both teams for putting on a good performance, and of course I express my gratitude to Sepahan who won the match at the end.
"We defended more and Sepahan devised more attacks throughout the game and it was natural the home side would increase the pressure as the game went on and they finally scored against us.
"This was only the opening match of the tournament. We have another five games to play and we will do our best to make up for this defeat in the upcoming matches."