La negociación fue dura y ambos equipos dieron diente con diente antes de firmar el contrato.

[details=“English Translation”]The negotiation was tough, and both teams clashed before signing the contract.
[/details]

Wiktionary has a quite different meaning for this idiom (and so does the RAE):

(idiomatic, dated) to have one’s teeth chattering (with cold or fear)

https://en.m.wiktionary.org/wiki/dar_diente_con_diente#Spanish

In another sentence in this collection, we have “echaron un pulso”, how about that?