Soares and Murray beat Colombia’s Juan Sebastian Cabal and Robert Farah 4-6 6-3 10-6 in one hour and 25 minutes.
It was their first ATP Masters 1000 title as a pair.
Soares and Murray won the Washington Open two weeks ago for their third victory this year, having defended their Acapulco title in March.
Soares and Murray have won nine titles since they joined forces in 2016, including the Australian Open and US Open.