By Legheri Onyamom
It was an open, attacking match and the best chance of the game fell for the hosts on 18 minutes, after Ifeanyi Inyiam's header left Frederick Obomate alone with Akwa United goalkeeper Victor Obiowo in the six yard box.
Obomate unbelievably shot over the bar, and a minute later Sharks were punished for missing such a sitter.
Godspower Anefiok's feeble shot from 25 yards took a slight deflection off a Sharks defender to deceive Olaide Okanlawo and give the visitors a shock lead.
The losses in their last two away matches appeared to have shattered Sharks morale and confidence as they struggled to put away chances to level the tie, although Obiowo made good saves from Inyiam and Obomate.
United on the other hand took their chances, and in the 33rd minute Ezekiel Bassey powered past Chima Akas on the right flank before displacing Okanlawo for the insurance goal.
The game developed into an ill-tempered affair with Pyagbara and Godspower Igudia getting their marching orders for an altercation in the 89th minute.
Sharks had lots of chances to come back into the game, but failed to take them till substitute Fortune Omoniwari fired home a free kick from the edge of the box in added time.
United coach Patrick Udoh was elated with the outcome of the match.
"We give God the glory for this victory. This (away victory) is what we've been looking for and now we have got one, we expect more to follow," he told supersport.com.
"We were once on top and we resolved before this game to start fighting our way back.
"With this victory, we hope to get back to where we belong in subsequent matches."
Sharks assistant coach Ere Dokubo was confident his team would bounce back from their third consecutive defeat.
"In football you win some and lose some," he said.
"There was a lot of pressure on the team and the players did their best. Unfortunately, it wasn't good enough.
"Akwa United played well and deserved to win, but I assure you we'll come back strong in the second round.
"We're still very much in the title race."
Sharks: Olaide Okanlawo, Odinga Odinga (c), Chima Akas, Gabriel Olalekan, Stephen Erewa, Joseph Nathaniel, Kelly Kester (Tayo Fabiyi 44'), Frederick Obomate, Christian Pyagbara, Ajani Ibrahim, Ifeanyi Inyiam (Chiamaka Madu 57', Fortune Omoniwari 81')
Unused subs: Danladi Isah, Yusuf Jaiyeola, Thompson Stowe, Ezekiel Michael.
Akwa United: Victor Obiowo, Otobong Effiong, Ubong Francis, Godspower Igudia, Uchenna Keke, Isaac Aileme, Ini Akpan (c), Michael Abasiome (Udibe Archibong 67'), Ezekiel Bassey (Emeka Akwueme 90+2'), Godspower Anefiok, Kufre Ebong.
Unused subs: Iboro Akpakpan, Akinwunmi Ogunboye, Friday Idara, Nura Nakargo, Charles Ovat