By Dave Bettley
Linnets delivered the perfect response to their Cheshire Senior Cup defeat at lower-division Congleton Town by convincingly overcoming opponents from two steps higher as LiverpoolCounty FA's equivalent competition returned to centre stage.
Vanarama National League North outfit Southport fielded a strong line-up in this second-round tie at APEC Taxis Stadium but never looked like repeating their pre-season win on the same ground.
The Sandgrounders have undergone a managerial change in the meantime with former Runcorn boss Liam Watson making way for ex-Morecambe manager, Jim Bentley, who saw his team hit the skids as dominant Linnets opened a surprising 3-0 interval lead.
Southport have other more pressing priorities, including an Isuzu FA Trophy visit this Saturday to National League leaders, Chesterfield.
But take nothing away from Linnets, who would have felt before kick off that they owed themselves and their fans a performance after well below par displays against Widnes in the league and last time out at Midland League Premier Division tabletoppers Congleton.
Liverpool Senior Cup finalists at their first attempt in 2022-23, Linnets had already shown intent to go one better this time when dismantling Runcorn Town 7-0 in the first round.
They clearly weren't going to be perturbed by the quality of Tuesday's opposition or indeed the icy conditions
A frozen pitch had put paid to Saturday's intended Pitching In Northern Premier League West home clash with Clitheroe, and a sudden early-evening dip in temperatures, after a couple of warmer days, gave rise to concern ahead of kick off.
The whitened surface might have looked tricky but it played true, without posing any real problems for either side.
Linnets looked the hungrier almost from the outset.
While few supporters, if any at all, would have predicted Linnets going into half-time with such a handsome lead, Runcorn made it a very difficult night for veteran 'keeper Tony McMillan.
Now largely concentrating on coaching duties, McMiĺlan was Linnets No.1 in ill-fated Runcorn FC Halton days, featuring in the FA Cup first round against Bristol Rovers back in 2002.
This reunion saw him concede within 11 minutes, being beaten by Olly Molloy's far-post header from a right-wing James Hooper cross, which had been helped on by Sean O'Mahoney.
Man of the match O'Mahony's strong central defensive partnership with Antony Kay was key to Runcorn's success as Southport's attack were kept quiet until very late on.
Having set up the first goal, Hooper scored the second from the penalty spot.
The kick was awarded for McMillan impeding Runcorn's very own Will O'The Wisp.
Will Saxon had ghosted past Southport's defence on the blindside in the 36th minute.
It got even better for the hosts two minutes later thanks to Adam Moseley seizing on a sliderule right-foot pass by left back James Short.
Moseley had been introduced in the 31st minute for Lewis Doyle, who appeared to have aggravated the hamstring niggle which had sidelined him in the last two matches.
Although not as fluent as they had been in the first half, Linnets continued to look the more threatening after the break.
The visitors took all of 65 minutes to put a shot on target and even that was routinely saved by Bayleigh Passant.
Linnets were denied the shutout they had promised when sub Alex Jones was deceived by a ball, which went over his head and into the path of Tyler Walton.
He, in turn, found Luke Burgess to his left for an 88th-minute Southport consolation.
But within 60 seconds, Linnets three-goal cushion was restored.
As an aerial tussle in the visiting goalmouth turned into an almighty scramble, Che Trapasso (another of the four replacements used by Billy Paynter) teed up right back Sam Barratt to complete the scoring.
Runcorn Linnets: Bayleigh Passsant, Sam Barratt, James Short, Jacques Welsh, Shaun O'Mahony, Antony Kay, Will Saxon (Alex Jones, 80 mins), Joe Lynch, Olly Molloy (Che Trapasso, 82 mins), Lewis Doyle (Adam Moseley, 31 mins), James Hooper (Mwiya Malumo, 64 mins). Subs not used: Peter Wylie, Josh Roberts (GK).