He also says: "Just the two of us". It is implied that they had a battle before but not on their own.
Following Vyzzuvazzadth analyses there appears to be a side mission after the first bombing mission, where Cloud goes with Biggs, Jessie and Wedge on a quest for possibly a summon materia. This would be the bike chase scene that we all have seen quite a lot. In this sequence Roche appears, and my guess is that they all defeat him together, while riding to their destination. He falls behind, but eventually catches up to the scene we see in the trailer and is now asking Clould for duel. After completing the mission the team parachutes back to Sector 7.
I think it's decent. It might fit an ending theme quite well (first desolation -> hope -> determination), Uematsu explained the image he conjured up when composing this track quite well. In general it's hard to make memorable themes, especially trying to integrate them into a game that already pretty much has the perfect main theme, which probably took Uematus months of refinement to finalise so that along with that and the general sound everything else harmonizes.
And you can't really compare this theme to the likes of Eyes on Me, Melodies of Life and Suteki Da Ne. They are the main themes of their respective games, so their magnitude and purpose is very different from Hollow.
