England's Ellis and Van Rietvelde, ranked as the 35th best men's doubles pairing in the world, won the Welsh International in December after finishing as runners-up at the Belgian equivalent.
And they were not to be denied a return to winning ways in Frederikshavn and in the final beat Danish pair Anders Skaarup Rasmussen and Kim Astrup Sorensen 25-23, 16-21, 21-19.
It was far from plain sailing though with Ellis and Van Rietvelde coming from behind in the first game and also avoiding four game points from the Danish duo.
Their opponents took control in the second game and were 14-11 ahead at one stage in the third however Ellis and Van Rietvelde fought back to claim the win.
The pair can now hope to move closer to a world top-30 place from their current ranking of 35th and a step closer to direct entry to World Superseries events.