The scores were tied 20-20 at the end of 80 minutes, and it was still a stalemate 20 minutes later, but because Boland scored five tries to EP's four in the final, it meant they remain the champions and finished the season unbeaten.
Credit to Eastern Province though, they never gave up and it was only some dogged defence by the hosts at the end that secured them the title.
The conditions were very bad - it was wet and windy and the field was very muddy - and that meant both teams made a lot of errors, while the pressure of playing in a final and some tired legs at the end also forced mistakes.
The Kavaliers scored three unconverted tries in the first half and followed that up by one more late in the second half, after EP had fought back to take a 17-15 lead.
With time up on the clock and the hosts leading by three, EP had a kickable penalty which Jayden Banton successfully steered through the uprights to push the game into extra time.
Boland scored early in extra time, with Ashlon Davids landing his first kick of the game to make it 27-20, but EP were not done and drew level again.
The Kavaliers knew the rules though and that they would be deemed champions if the scores were tied, and they hung on to seal the deal.
It was a special day for Boland coach Hawies Fourie too, after he won the Carling Currie Cup Premier Division with the Toyota Cheetahs last year, and followed that up with the First Division title on Saturday.
Scorers:
Sanlam Boland Kavaliers 27 (15) - Tries: Neil Rautenbach (2), Dayan van der Westhuizen, Cornell Engelbrecht, Taine-Randall Booysen. Conversion: Ashlon Davids.
Eastern Province 27 (10) - Tries: Temba Boltina, Lungi Mbiko (2), Wayne Ngubane. Conversions: Jayden Bantom (2). Penalty goal: Banton.