Not many teams leave Ravenhill with a win, but the second-string Ospreys muscled their way to a 20-12 victory that Holley says is a turning point in their season.
"We didn't start the season well, probably because we were in a new home and we had a lot of injuries to key players, but I think you've seen the real Ospreys in the last couple of weeks," he said. "The win in Ulster was brilliant - we had about a dozen players missing, but the other guys really dug deep. Not many teams will win in Ulster this season and it was a very nice feeling to return with the points."
Holley said the defending champions had no intention of taking their hands off the Celtic League trophy just yet.
"We're about sixth on the table and I think a lot of the top teams will take points off each other. And looking at the draw, about seven of our last 10 games are at home. We know we can't afford to lose too many more games, but it's a bit early to write us off just yet.
"Our next game is the Powergen Cup match against Bristol on December 2, and - touch wood - we should have a full compliment of players back by then. The likes of Gavin Henson and Ryan Jones are targeting that match, and I don't think many teams will be looking forward to playing us when all our players are fit."
Outside-half Shaun Connor - who is enjoying the best season of his career - was again the Ospreys' hero on Friday night. He slotted four penalty goals and a clever dropped goal to compliment the effort of scrum-half Jason Spice, who scored the only try of a hard-fought match.
As the countdown continues for RWC2015, Tournament Chief Executive Debbie Jevans visited the Millennium Stadium to discuss preparations for the eight matches and reveal the positive news that 100,000 tickets for games at the home of Welsh rugby have sold in the last seven days.
Jason Harries is targeting a first win on the World Series circuit this season with Wales. The series returns to action this weekend in Dubai where Harries is part of a team hoping to build from its efforts in round one in October.
Wales skipper Jevon Groves says his side have addressed a few points from Gold Coast and aim to 'hit the ground running' in the next two rounds of the World Series, kicking off with this weekend in Dubai before heading off to South Africa next week.
Wales Sevens manager Steff Thomas is hopeful his side can build from a quarter-final spot in the opening round of the World Series in Australia when his side take part in the forthcoming double header in Dubai and South Africa.