They had a match somewhere in their last year of primary school or 1st year in jr. high. It is when Sanada said Tezuka is on par with Yukimura.

yes,in primary school.l do not know who wins,in the match,tezuka defeated sanada and then met yukimura.
I have heard that yukimura was the champion,but I do not know if that was true

they have a match about years ago and i dont know if tezuka is already the captain of seigaku back in that time. tezuka defeated the emperor- sanada and when yukimura saw it, he challenge tezuka to have a match with him. tezuka didnt refuse but i dont know who won in that match because its not stated in the manga