Not very advanced yet in my own training, but here is my first "grab" at it.
yokomenuchi attack...(right hand)
tenshin with block (left hand) - atemi with right. continue to bring right hand over the attacking arm as the left slows the attack by blending.
grasp hand as in ikyo versus the lapel grab ..
(katatori?) and open the hips to your right to take balance and perform ikyo in the standard omote version. (or ura, if you prefer)
I have no doubt that there are MANY ways a more sophisticated aikidoka could achieve this, but I am not too "opinionated" to allow the differances.