Enduro racing mixes aspects of downhill and cross country racing where riders complete timed stages, which count towards their overall time.
About 430 riders took part in the opening race on Saturday in near perfect conditions.
Gellatly said Raewyn Morrison (Nelson) also raced brilliantly to take out the women's title, winning five of the six stages in the women's race.
Both Wright and Morrison are now in the running for a $10,000 prize.
Sponsors Ray White Real Estate have put up the cash incentive this year for anyone who can win all three events during the series, in either the men's or women's division. If both a male and female rider achieve the feat they will split the prize and get $5000 each.
"Obviously Keegan and Raewyn are the ones that have lined themselves up for the Ray White $10k Slam prize," Gellatly said. "If they keep performing like they did on Saturday then they have a good showing to win it, but it all depends on who else enters."
Morrison is an experienced enduro rider and is currently ranked ninth in the world in the mountain bike discipline.
-Giant 2W Gravity Enduro results from Saturday (after all six stages):
Men's race: 1 Keegan Wright (34min 48sec), 2 Matt Walker (35.14), 3 Sam Shaw (35.41), 4 Carl Jones (35.57), 5 Daniel Self (37.02).
Women's race: 1 Raewyn Morrison (40min 45sec), 2 Annika Smail (41.20), 3 Janine Kavanagh (43.45), 4 Katie O'Neill (43.58), 5 Aly Bennett (45.04).
