Thistle boss Stuart Davidson has made a rally call for supporters to get to Barrfields this Saturday and back his young side as they take their first step in the Macron Scottish Cup this season.
Largs, who reached the cup final of the national competition last season, face Luncarty in a 2.30pm kick-off, and it is a case of Friends Reunited as both sides have met each other during recent years in pre-season friendlies.
Largs triumphed 3-2 in July in an exciting attacking encounter.
Davidson said: "If you think of our great cup run last season and the crowd who came to the cup final it was phenomenal.
"The crowd who came to the quarter final against Kilwinning in the quarter final was terrific too - it was the same with the Hurlford semi-final. We are looking for similar strong backing.
"A big crowd makes a massive difference - and it is the biggest game of the season for us so far. 
"If you look at the joy Thistle brought to the town last year it is important to get a good cup run - the boys who played in want more of it, and the new boys want a taste of it.
"It adds a lot to the season with players pushing for places wanting to be involved in the big games."
Adding further spice to the encounter is the fact that both managers are good friends.
Davidson said: "Luncarty manager Joe Kelly and I go back many years but we are both very competitive and want to win whether it is a game of table tennis or pool on holiday!
"The same applies when it comes to the Scottish Cup!