A few years ago I watched a student practice suwariwaza shomenichi ikkyo with Saotome Sensei. Each time, the student began moving before Saotome did and the student moved faster than Saotome did, yet Saotome Sensei's hand arrived at the perfect meeting point before the student's hand arrived there.
Reminds me of a passage from Karl Friday's Legacies of the Sword
[w]hat matters most is not which opponent is faster or more powerful, but which is faster or more powerful at the critical moment in which a blow is delivered.
This passage along with more thoughts on the topic (including a nice little figure/graph) is luckily included in Google Books here: http://books.google.com/books?id=JXfVINMfbx8C&printsec=frontcover&source=gbs_summary_r&cad=0#PPA71,M1
. The rest of the book is worth reading as well, of course.