https://ballotpedia.org/Washington_Treasurer_election,_2016
Duane Davidson (R) won against Michael Waite (R) after 3 democrats split the vote in the primary:
Republican Duane Davidson 25.09% 322,374 Republican Michael Waite 23.33% 299,766 Democratic Marko Liias 20.36% 261,633 Democratic John Paul Comerford 17.97% 230,904 Democratic Alec Fisken 13.24% 170,117
If outcomes in general are better, I'll take the risk that they're occasionally worse.
https://ballotpedia.org/Washington_Treasurer_election,_2016
Duane Davidson (R) won against Michael Waite (R) after 3 democrats split the vote in the primary: