The nine-year-old was conceding weight all around in the three-mile affair, but was still sent off the 2-1 joint-favourite under Richard Johnson.
La Bague Au Roi led from the outset, but was joined by both the Keith Dalgleish-trained Amalfi Doug and Lucinda Russell’s Elmono over the third-last fence.
After shaking off the latter, La Bague Au Roi and Amalfi Doug drew level on the approach to the final obstacle, where Greatrex’s mare clambered through the fence and handed the race to her challenger.
Watch how La Bague Au Roi fared on her seasonal return at Perth on Wednesday
Amalfi Doug went on to triumph by seven and a half lengths, with Elmono second and Dan Skelton’s Very First Time a further three and three-quarter lengths behind in third.
La Bague Au Roi finished a further nine lengths behind in fourth place, but Greatrex felt she would have been closer were it not for her late error.
He said: “She seems fine after the race, which is the main thing. Everything was generally going to plan until the last when she came to a bit of a halt and just couldn’t get going again after that.
“Dickie said she felt like she had all her old enthusiasm, she jumped well enough in the main and galloped from fence to fence, but he said we might just want to get her wind checked out. She had it done two years ago and it’s not been looked at since.
“It was a lot of weight to give to the winner, who has had a few runs and was match fit. Coming into the race, I said I would be happy if she was in the first three and I think she would have been, but for the mistake at the last.
“We’ll take her home, get her wind looked at and see where we go from there. The plan was to have a look at the Ladbrokes Trophy and I still think that race could suit her, back at Newbury where she has won before.
“I still think she’s reasonably treated and if tinkering with her wind could bring a bit more improvement, that might be the race.”
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