Sam (8), a pupil at Waiwera South School in South Otago, and Dewy, were first to run in the junior barrel race.
Eighteen-year-old Dewy - who Sam said could be very naughty - kicked out quite a few times on his way around the barrels, but his determined young rider was unfazed.
Sam, who has been riding since she was 2, is in her first season of barrel racing.
She competed at Millers Flat on Friday, Omarama yesterday and will also head to Wanaka and Te Anau.
Horses are a family affair for the Spences.
Sam's parents, Gus and Julie, met on the hunt field, while Dewy belongs to Sam's brother Ben (6) who was entered in the calf ride.
Mr Spence competes in the rope and tie, while his brother Jock Spence, a bull rider from Gisborne, has been doing the North Island rodeo circuit but is heading south for the Wanaka rodeo.
Sam is also a keen eventer, riding her pony Billy, but said barrel racing was her favourite discipline because it involved speed.
The young cowgirl was disappointed with her attempt at Waimate, saying she was "way slower" than at Millers Flat.
Fine weather saw a large crowd attend the rodeo at the Waimate A and P showgrounds, and the bucking broncs and bulls did not disappoint.
Results.
-Open, bareback: Scott Mayberry (Darfield) 1, Anthony Thomas (Australia) 2, David Batty (Ashburton) 3.
Bull ride: Adam Jamison (North Canterbury) 1, Ross Dowling (Christchurch) 2.
Rope and tie: Nev Sarginson (Darfield) 1, Michael Sanderson (Middlemarch) 2, Patrick McCarthy (Christchurch) 3.
Saddle bronc: Simon Roughan (Lawrence) 1, Larry Williamson (Dunedin) 2, Steve Houston (Ashburton) 3.
Barrel race: Alyce Peek (Christchurch) 1, Elaine Gubb (Middlemarch) 2, Ginny Nelson (Wanaka) 3.
Steer wrestling: Daniel Devine (Oxford) 1, Scott Glassey (Christchurch) 2, Anthony Perkins (Gore) 3.
Team roping: Patrick McCarthy and Nev Sarginson 1, Anthony Perkins and Murray Hellewell (Tapanui) 2, Scott Mayberry and Nicole Sarginson 3.
Second division, bareback: Richard Harden (Mokau) 1, Craig Dunlop (Marlborough) 2, Dave Murray (Ashburton) 3.
Barrel race: Olivia Ross (Middlemarch) 1, Allison O'Connell (Christchurch) 2, Teresa Lunn (Alexandra) 3.
Saddle bronc: Garrick Scally (Waikouaiti) 1.
Bull ride: Gary Topping (Mosgiel) 1, Sam Caley (Ashburton) 2, Michael Wood (Waimate), Nick Burnett (Ranfurly) and Robert Olsen (Australia) 3 equal.
Junior barrel race: Paige Church (Palmerston) 1, James Pinfold (Darfield) 2, Kimberley Thomas (Middlemarch) 3.
Junior steer ride: Laurie Hawea (Roxburgh) 1, Cody Davis (Rotorua) and Cameron Thomas (Middlemarch) 2 equal.
Calf ride: Lane Church (Taupo) 1, Luke Longley (Outram) 2.