Wallace High started favourites but towards the end the result could have gone either way as the home team bombarded their opponent's line without success.
Robbie Reid was in excellent form for Belfast High School and he kicked an early penalty but then a defensive mistake allowed Wallace to not only take the lead but gain a psychological advantage.
A defensive clearance kick was charged down and scrum-half Jonny Stewart crossed for an unconverted try.
The visitors had the territorial advantage at this stage but another infringement in their opponent's half allowed Reid to regain the lead with a second penalty.
The move went through numerous phases and helped by some slack defending Jordan Garford crossed for Reid to add the points.
This gave the home team the incentive they needed and went on to take a 13-5 interval advantage although, as it turned out, that was not enough when they had the wind in their favour.
There was little between the teams during the first 10 minutes of the second half, although both teams conceded a number of penalties.
Wallace kept the ball tight and reduced the arrears when Josh Collingwood barged over to make it 13-10.
Then it was the turn of Jacob Stockdale to show his pace when he cut through a couple of tackles to go over in the corner.
Ryan Moore added the difficult
conversion and the Lisburn team were ahead for the first time.
Moore then kicked a long penalty from the 10 metre line but the home side kept going to the end.
“We were firmly encamped on their line for the closing minutes but just couldn't get over,” commented High School coach Mickey Rainey.
“It was a tight game between two decent sides. I was pleased with the way we controlled the tie but would have liked to have been further in front at the interval.
“Either side could have emerged victors but I give full credit to my team who gave everything right to the end.
“In the last ten minutes we were inside their 22 but their defence held. I must mention our captain Lewis Benson.
“His was a good all-round performance and a key player like Robbie Reid who kept us in the contest.
“Unfortunately we missed a few vital tackles when they were having their purple patch but they had a couple of outstanding players in their scrum-half and No 13 who caused us a lot of trouble.”
Wallace coach Neil Hinds was happy to come down to Newtownabbey and come away with a win.
“I thought we were very motivated and well-drilled. A good team effort under the leadership of Callum Irvine who has just returned from injury,” he said.
“There was some smart and intelligent play and all credit to the High School as we had to delve deep towards the close.
“They are a fantastic team who caused us a lot of problems
“We are still not at full strength due to injury problems but hopefully a couple of those guys will be back for the next round.”
Wallace will be glad to have home advantage when they meet Campbell College.