'Dexter' grad Clyde Phillips has exited the Billy Bob Thornton drama and is being replaced by exec producer Lawrence Trilling.

Amazon's Goliath is seeing another behind-the-scenes change.

Showrunner Clyde Phillips (Dexter) has exited the drama after joining the Billy Bob Thornton starrer for season two. He will be replaced by exec producer Lawrence Trilling, who worked on season one of the series.

Sources say Phillips — who replaced David E. Kelley as the day-to-day showrunner on the series — and his writing team had written all 10 episodes of season two with Amazon and Thornton both signing off on scripts.

The creative rift happened after Thornton, sources say, was unhappy with how the season two premiere turned out. Production on the series was shut down and Phillips opted to step down rather than re-arc the entire season. Sources note the first four episodes of season two had been completed and were in editing. The season two premiere is now being rewritten and reshot and three episodes will be scrapped, bringing the season tally to seven. Production will resume Wednesday.

That's similar to what happened with season one, which initially was also poised to be 10 episodes but finished with eight after showrunner David E. Kelley, who developed the series, was pushed out of the day-to-day role and a revamped episode three became the show's pilot.

The changes will mean the legal drama will likely extend beyond its planned season two budget, a fact that sources note is becoming increasingly worrisome at Amazon. That brings the per-episode cost to almost $10 million, and the budget overage to about $65 million, sources say.

The retail outlet and streaming service previously indicated Goliath was its most-binged show in its first month of release. It was also Amazon's first show to score a straight-to-series order and avoid the pilot-voting process. Thornton earned a Golden Globe for his performance.

Goliath becomes the latest Amazon show to see a showrunner change, joining Man in the High Castle, Bosch and Sneaky Pete.

A premiere date for season two has not been determined.

Trilling (Parenthood, Alias) is repped by CAA.