Tac De Boistron took Group One honours for trainer Marco Botti and jockey Martin Harley with a convincing victory in the Prix Royal-Oak at Longchamp.
Runner-up in the Prix du Cadran on his previous start, the six-year-old grey appreciated the drop in trip to just under two miles in the French St Leger. Tres Rock Danon made the running well into the home straight where Harley unleashed Tac De Boistron to sweep into the lead on the outside and win by five lengths.
Going Somewhere was second while Irish challenger Missunited put in excellent work at the finish to get third for Michael Winters, just three-quarters of a length away.
“He won well. This is his ideal trip – the Cadran was just a little bit too far for him,” said Botti.