With just one goal separating the sides in the Irn-Bru First Division standings, this weekend's first versus second battle is one of the games of the day.
And while Jags defender Muirhead is no stranger to pressure occasions in the race for promotion, the 22-year-old reckons the Pars clash will top them all.
He said: "I have been pleased with my form. I was a bit shaky at the weekend, but hopefully I can get back on track. I would say it is the biggest match I have ever played in, and it is these kind of games you look forward to the most.
"When I was with Annan, the play-off finals were big games in front of big crowds, but nothing has been as big as Saturday."
With seven wins from their opening 10 league fixtures, including a 1-0 win at East End Park, Thistle have laid down an early marker of their promotion intentions.
Jackie McNamara's side took a break from league duty to book their place in the William Hill Scottish Cup fourth round with a 2-1 win over Cove Rangers last weekend and Muirhead can't wait to get back to the title race.
"It is a huge game for us," he said. "Everyone has been talking about it, from the fans right through to the boys in the dressing-room. The focus is certainly on Saturday. We will just go about it the same as we do in any game, we will try and win.
"I don't know whether Dunfermline will come and sit in or whether they will take the game to us.
"I would imagine a point would be a decent result for them, especially with our home record, which has been good and we want to keep that up.
"Picking up wins at home is going to be important for us, so we will keep attacking teams and hopefully scoring goals."
There has been plenty to cheer for the Firhill crowd as they have seen Jackie McNamara's men win all seven of their home clashes in league and cup, firing in 24 goals as they have dazzled on familiar territory.
The Jags will wear their traditional red and yellow colours for the first team this season against the Pars, and Muirhead hopes the help of Thistle's 12th man can see them regain pole position in the title race.
He said: "The fans have been great. It is always a lift when they get right behind you. It is certainly something I have noticed.
"I think there will be an even bigger crowd than usual. It is great to have the fans behind the goal as well.
"It is a massive game and three points would be huge for us. It would give us a three-point cushion on the team closest to us and then we can look to kick on from there. Dunfermline have had a great start and that just shows how big a game it will be for both teams."