Ash has 3 pokemon left (Pikachu, Infernape, Gliscor) and Paul has 2 (Drapion, Electivire).
The confirmed match-ups in this episode are:
Gliscor VS Drapion
Pikachu VS Electivire
Infernape VS Electivire
Also, assuming Gliscor wins...
Gliscor VS Electivire
If Gliscor loses...
Pikachu (or Infernape) VS Drapion
Then there could be the draw.
I see this as the most likely option, since we didn't get a hint of the other two possibilities in the preview.