In front of a 400-plus crowd and sweltering in 23 degrees of sunshine, Cuikie with two wins against the Burgh already this season, looked to complete the hat-trick to become champions.
But the East Lothianers were to pose a huge hurdle for Penicuik, who missed a number of chances to break the deadlock, before Musselburgh took theirs and set up a nervy finale.
However, following a second yellow and subsequent red for Burgh’s Liam Reid on 77 minutes, Cuikie finally got a simple tap-in goal to equalise, and held on to secure the point and win the league with huge celebrations at the end.
They will now play in the Championship play-off alongside Bonnyrigg Rose and Broxburn.
The hosts’ strong start was promising but brief and it was the visitors who had no fewer than three early chances. Firstly, Nathan Evans fired a fierce shot wide on five minutes, then a second chance fell to Jackie Myles, but he side-footed wide, before a Mathu King header was well saved by home keeper Robert Watt.
In between Sam Jones had been clean through for Penicuik but Burgh keeper Ali Adams denied the chance, blocking with his legs.
Penicuik did enjoy a better spell of possession after that but the opening goal continued to prove elusive at both ends. A Conor Thomson free kick was forced away for a corner from which the ball came to Michael Deland but he lashed the ball over the target.
In 32 minutes Wayne McIntosh was clean through but again a brilliant stop by keeper Adams denied the Penicuik striker. In contrast to anxious Cuikie, The Burgh were more relaxed with the pressure on the hosts telling as the first half ended with a Jordan Caddow chance hit wide.
The big home crowd were looking for an improved Cuikie second-half display, but following a goal line clearance in the Burgh penalty area, they were shocked on 54 minutes as Musselburgh went 1-0 up through a composed finish by Myles, beating Watt low down to his left with an accurate shot.
Penicuik certainly did not want to concede that goal adding more pressure to the home ranks with the Burgh looking to extend their advantage – a Deland shot was well parried by Watt before at the other end, another blocking save by Ali Adams thwarted McIntosh.
But the game changed in the 72nd minute when Burgh were reduced to 10 men with Liam Reid sent off for a foul and second yellow.
Cuikie capitalised on the man advantage as McCrory-Irvine drew the hosts level with 13 minutes to play. It was nail biting stuff with a Callum Connolly header missing the target for a winner and in time added on a Wayne McIntosh shot saw a final save by Adams. On the final whistle it was huge relief as the champions celebrated.
Penicuik: Watt, Stevenson, Baptie, Young, Page, Connolly, Caddow, Jones, McIntosh, McCrory-Irving, Ponton. Subs: Williams, Sampson, Notman, Somerville, Crabbe, Hamilton, Cordery.