Two-goal Kirk Millar believes Linfield will learn from their mistakes from Tuesday night's 4-1 County Antrim Shield win over Ballyclare Comrades at Dixon Park.
David Healy's boys may have booked their place in the second-round draw, but they almost paid the ultimate price after taking their foot off the gas.
The Blues got off to the best possible start with Stephen Lowry and Millar both netting inside the opening 12 minutes, but they duly gifted Comrades striker Mark Kelly an opening just before the break - one he put away with a certain degree of panache - and were left holding on at times in a frenetic second half.
It wasn't until Millar bagged his second of the night nine minutes before the finish that the visiting fans could afford to stop peering through their fingers.
And those supporters then breathed a huge sigh of relief when Louis Rooney finished the job five minutes later.
Yes, it finished comprehensive, but the scoreline camouflaged a sloppy, ragged and uncharacteristic performance from the Irish League champions.
"We came down here a few years ago when Warren Feeney was boss and were chinned in the League Cup, so we knew what to expect," said 25-year-old Millar. "We knew it would be a tough game.
"But we made it difficult for ourselves. We got off to a great start, scoring twice in the opening 12 or 13 minutes. I thought we would kick on and finish it.
"However, we certainly ended up having to work a lot harder than we expected.
"They got their goal at the right time, just before the break. And they took a lot of confidence from it.
"Ballyclare came out for the second half and had a right go at it. Even when they conceded the early goals, they never threw in the towel. We were more clinical in front of goal and that was the difference."
Millar admits the Blues cannot afford to make the same mistakes when they travel to Warrenpoint Town for a Danske Bank Premiership showdown tomorrow night.
He added: "It's another big game. We have to go off on another winning run after the defeat at Crusaders last week.
"Winning is the best thing for building confidence. I know Warrenpoint are on a sticky little run at the minute, but they have good players.
"Matty Tipton has brought in a lot of experience and they'll be difficult to beat. We go into every game expecting to win it, so this one will be no different.
"Every player has a challenge at this club - and that is holding down a first-team place.
"The competition helps drive everyone on."
• FORMER Linfield striker Kris Bright has signed for Auckland City in New Zealand.
The 31-year old, five-times capped for the All Whites, signs as a free agent after leaving Windsor Park in the summer.