Montler had not jumped over eight meters tonight but stood at 7.94 before the final round when the full hit of 8.21 came.
Tentoglou had jumped 8.15 in the last round and finished with an invalid jump.
On Friday, Montler jumped 8.00 and 8.02 when he won the season premiere in Karlsruhe.
Today's result is one decimeter from his Swedish inner record of 8.31 and he is third on this year's world best list, where the Swiss Simon Ehammer leads at 8.26 before the American Matthew Boling who jumped 8.25.