Ouch, not nice. Honestly I would give it a few days then call it quits and say it hasn't worked, thus it wasn't due to the first nap. The other option is to go the other way...could be really really OT and needing extra daysleep? It's really really hard to work it out, and often it's trial and error.
Are you needing to go into him at the EWs, have you tried just leaving him be (if he0s not unhappy) ? I say this because early morning sleep is a very light sleep so he may just need longer to get back to sleep. On that note, have you checked out everything to do with the room? Too much light? too hot? too cold? a noise? something waking him?