In the 500 metres, where he has already qualified for the A Division, Grieg finished 18th for the second consecutive day.
On the opening day of the Nagano program, the Australian Institute of Sport scholarship holder finished fifth in the B Division 1000m. But he was much quicker on the Sunday, winning his race and also setting the 13th fastest time from all-comers over the distance.
His Sunday time of 1 minute 10.71 seconds was 0.34 seconds quicker than his Saturday race.
The victory qualifies him for Division A for the coming 1000m World Cup in Harbin, China, next weekend.
Greig also raced the Team Sprint on Sunday in a joint team with the Netherlands' Jesper Hospes and Ronald Mulder placing fourth..