Rhys Mariu and Harry Chamberlain were soon scoring freely to make it to 27 in the sixth over before Mariu also departed, also caught off the bowling of Stoyanoff.
About 4.15pm, Canterbury Country was 30-2 in the ninth over, and eventually ended the day 87 for 4 off 35 overs, with first innings honours seemingly inevitable.
Stoyanoff ended with 2-24 Liam Dudding and William Clark picking up a wicket apiece.
Having waited for the Central Districts Stags to have first pick ahead of a first-class Plunket Shield match starting in Nelson on Saturday, HB selector-coach Christie van Dyk was still able to name an experienced side including Angus Schaw, playing his 99th senior match for the association, Stoyanoff (79th), Dominic Thompson (56th), and Todd Watson (54th).
Teams for the match are:
Hawke's Bay: Jono Whitley, Jack Boyle, William Clark, Dominic Thompson, Angus Schaw(captain), Brett Johnson, Scott Schaw, Todd Watson, Jayden Lennox Liam Dudding, Ben Stoyanoff, James Rinzler (12ᵗʰ man)
Canterbury Country: Rhys Mariu, Zak Foulkes, Harry Chamberlain, Jesse Frew, Tim Gruijters, Matt Laffey, Archie Redfern, Will Williams, Blake Coburn, Sam Chamberlain(captain), Alister Collins, WH Smith (12ᵗʰ man)
Meanwhile, Hawke's Bay women's captain Sophie Pyott will lead the Central districts women's second eleven (Central Districts A) in two short-form games against Northern Districts in Hamilton during the weekend - a T20 match on Saturday and one-day limited-overs game on Sunday.