Paineñamcu or Paynenancu or Alonso Diaz, was the Mapuchetoqui from 1574 to 1584. Alonso Diaz was a mestizo Spanish soldier offended because the Governor of Chile did not promote him to the officer rank of alféres, who subsequently went over to the Mapuche in 1572. He took the Mapuche name of Paineñamcu and because of his military skills was elected toqui in 1574 following the death of Paillataru.
He was captured in battle in 1584 and saved his life when he betrayed to his captors the location of a renegade Spaniard and a mulato that were leaders in the Mapuche army. He was executed later that same year in Santiago, Chile when the Spanish believed he was communicating with the rebellious Mapuche. Cayancaru succeeded him as toqui after his capture.