Connor McCloskey won the Down Rally to set up a final round shoot-out for the Northern Ireland championship.
But long-time series leader Sean Devine was left fuming after twice being involved in incidents with slower cars, the second of which forced his retirement.
The rally organisers had elected to run cars in the 1400cc class at the front of the field and Devine dropped over half-a-minute behind one of them on the third stage.
But the real trouble erupted on stage six when he came across another one which was beached on rocks and partially blocking the road.
In attempting to squeeze past, his Subaru slipped off the forest track and then became bogged down.
The combination of the stranded 1400cc car and Devine's Subaru blocked the stage, thus forcing the following crews, including rally leader McCloskey, to stop their cars and assist in clearing the road.
They were able to get the Subaru mobile again but the steering had been damaged and, although the stage was subsequently cancelled because of the delays, it was no consolation to Devine who was forced to retire.
But McCloskey had led from the start and was 16 seconds in front when the sixth stage incident happened despite losing over 20 seconds when he stalled his Ford Focus on the startline of stage four.
For McCloskey, who went on to win comfortably from the Mitsubishi Lancer of Cathal Rogers with John Walker third in another production Mitsubishi, it was his second successive win of the series.
And with 2007 champion Glenn Allen failing to start Saturday's FM Contracts event, the championship will be fought out in a winner-takes-all duel between McCloskey and Devine on the final round, the Townparks Rally, on November 1.