Good luck with that! We had an awful 2-1 transition, too. NWs were a huge part of that transition. If it makes you feel better, our NWs disappeared after a month of being firmly on 1 nap, and haven't reappeared since then (maybe once a month he might have a brief waking).
The technique that seems to work best during the 2-1 transition is to limit the AM nap to no more than an hour at first so that you can still get that PM nap in, if it's still needed. As you're finding, more than an hour and your child isn't tired enough for a PM nap. You may even need to shorten the AM nap to 45 minutes or 30 minutes to get a proper rest in the PM. You'll slowly move the AM nap later, until you have a nap somewhere between 11 am and 12 pm, and then you just stick to one long nap in the PM. Bedtime might be super early for awhile (it was 5:30 for Owen for a few days!), but awake time will slowly lengthen until bedtime is moved back to a more normal 7/7:30.
I hated the idea of waking Owen from a nap, but the advice given my other BWs to do the above was the best advice EVER! It took us into at least a more predictable phase rather than the crazies we were going thru before I shortened the nap!
Good luck! This is SUCH a tough period, but on the other side is blissful 1 nap land!