UFC's Derrick Lewis: Houston Needs This World Series, Still Hurting from Harvey

UFC star Derrick Lewis says an Astros World Series championship would be HUGE for Houston ... 'cause it's exactly the boost his city needs after Hurricane Harvey.

"We need the money," Lewis told TMZ Sports. "All the bars and the sports stores ... hopefully we continue doing great things and they'll dish it back out to the city."

He would know -- in the weeks after the hurricane hit, "The Black Beast" went full Dark Knight, abandoning fight camp to rescue flood victims in H-Town.

Derrick says he ain't too concerned about this series, though -- 'cause the Dodgers won't take A SINGLE GAME from the 'Stros!

"I believe we'll sweep 'em, 4-0 ... mark my words."

Dodger fans obviously see the series going very differently ... including Blue Crew lifer Danny Trejo, who told us why it's L.A.'s year.