Chevron Corp. won its arbitration battle with Exxon Mobil Corp. and has closed its $53 billion deal to buy Hess Corp. more than 20 months after the takeover was announced.

Chevron has scored a critical ruling in Paris that has given it the go-ahead for a $53 billion acquisition of Hess and access to one of the biggest oil finds of the decade.

It’s a big win for Chevron. Buying Hess without the Guyana project would have wiped out the biggest upside from the deal.