Ashes to Ashes - Undying Tenacity

Can i trigger the Undying Tenacity-effect with Ashes to Ashes, and in that case will i recieve the two blood and untap?

Ashes to Ashes ends combat, thus rendering Undying Tenacity useless.

The following happens, by what can be read from the card text:

Damage is dealt. Ashes to Ashes is played. Damage is prevented. Player decides to play Undying Tenacity, which allows combat to continue until combat ends. Ashes to Ashes ends combat, and the vampire gains 2 blood, untaps and finds himself in Torpor.

Am I wrong here?

Quoting card text enables quick understanding.

Ashes to Ashes
Combat
Thanatosis - Fortitude
Only usable by a vampire being burned; he or she is sent into torpor instead.
Prevent all damage. This vampire untaps and goes to torpor (ending combat).
As above, and this vampire gains 2 blood from the blood bank.

Undying Tenacity
Combat
Fortitude
Only usable when this vampire should go to torpor. This vampire will not go to torpor until after combat ends (although he or she is still wounded and can be burned by aggravated damage).
Press or prevent 1 damage.

The going to torpor part is what ends the combat, not the preventing damage effect. If the vampire plays Undying Tenacity to continue the combat instead of going to torpor, then additional strikes or presses could be played as appropriate, and the victim could play another Ashes to Ashes against those additional strikes.

Watch out for that Trap!

Trap
strike hands
Ashes to Ashes (gain 2 blood) / Undying Tenacity
press to continue from Trap
strike hands
Ashes to Ashes (gain 2 blood) / Undying Tenacity
press to continue from Trap

etc.

Not the best way to spend a minion with superior Thanatosis, but good for a laugh or two.

i like to laugh....

so ur saying that in addition to reciveing the two blood i untap aswell?

And would i need to play trap? the UT gives a similare effect right?

The vampire would both gain blood and untap, yes.

The Undying Tenacity doesn't provide a press at , and the version doesn't include 'As above'.

The combat will end at the end of the round unless another effect provides a press.

hmm how about Undead Persistence?