Tonny was in a good vein of form ahead of the huge clash against a fellow finals contender, the Blues having won five and only lost once since a round one loss to Nathalia.
The match was expected to be close and followed that script early, as neither side was able to create genuine separation on the scoreboard, though Rumba held a three-goal advantage at the first break.
Each side was able to go on a run in the second, Tongala first netting eight of nine goals between the 20th and 25th minutes before Rumbalara closed the half by scoring eight of 11, leading 28-26 at half-time.
The Blues started the stronger in the second half, scoring 11 of the first 14 goals in the third quarter to at one stage open up a six-goal lead, though Rumba slowly halved that deficit ahead of the fourth as Tongala held a slender 42-39 advantage.
Rumbalara pushed hard to overturn the margin during the final period, the score at one stage 47-46 before the Blues produced a run that would ensure their victory.
Tongala scored six of seven goals between the 52nd and 57th minutes to reinstate a six-goal lead and the Blues held on despite Rumba netting four of the final five goals, winning 54-51.
Milly Brock led all scorers for Tonny with 26 and Chicquita Vick contributed heavily with another 23 goals.
The Blues are now up to third on the ladder having won six of their past seven, ahead of fourth-placed Moama on percentage, but only a win off second-placed Mulwala.
Tongala is still two wins off league leader Nathalia, which is one of only two sides it has lost to, and the Blues and Purples will reacquaint themselves with each other next in what should be a close round 10 encounter.