Westbrook, 28, now has the biggest total contract in National Basketball Association history, totaling $233 million over six seasons including 2017-18.
Until Durant's free-agency flight to Golden State a year ago, he and Westbrook were OKC teammates for eight seasons.
Furthermore, the deal is for the Designated Player Veteran Extension, which allows Westbrook to sign for 35 percent of the salary cap and five additional seasons.
Yet Oklahoma City has also agreed to give the richest contract in National Basketball Association history to a player who will turn 30 early in the first season of the deal. Westbrook said this week that Oklahoma City is where he wanted to be.
Westbrook will make a total of US$233 million (AU$297 million) over the next six years - the biggest guaranteed contract in National Basketball Association history. Thunder fans may have been on pins and needles, but if Russell Westbrook has proven anything over the course of his nine-year National Basketball Association career, it's that when the chips are down, he's the guy you want in your corner.
Primarily because of Westbrook, the Thunder's marketability was sustained even after Durant left. "I was just running down the street a while ago talking about Russell Westbrook and the police pulls me over and asks me if I'm alright!"
Leader praises revived GOP health law repeal drive
The bill would also place a federal spending cap on Medicaid , which is jointly funded by the states and feds, for the first time. He added: "I hope Republican Senators will vote for Graham-Cassidy and fulfill their promise to Repeal & Replace ObamaCare ".
The deal signed Friday begins with the 2018-2019 season.
When Durant bolted for Golden State, Westbrook became the man in Oklahoma City.
The Thunder have a much brighter future ahead of them than they had just a couple of weeks ago. I chronicled the evolution of Russell Westbrook from reckless rookie to riveting league MVP.
Westbrook is coming off the best season of his career thus far, averaging a triple-double, in which he ran away with the NBA's MVP award. Although they know Westbrook was interested in staying with them long-term, they knew that the stakes would be higher this time around regarding contract negotiations.
Curry's $201 million deal had been the biggest. Westbrook was not giving any indication about which direction he was leaning in regards to the contract extension.
In spite of Oklahoma City being the NBA's second-smallest market (larger only than Memphis), the Thunder is among the NBA's top four teams in revenue generated from corporate sponsorships.