The Rockets won a hotly contested Game 4 against the Blazers on Sunday night, moving them to within one victory of the second round.
Houston, who hasn't won a playoff series in 12 years, has been one win away from advancing on a few occasions in the past.
"We still have one to go," center Yao Ming said. "We've been in this situation before."
Game 5 is Tuesday night in Portland as the Rockets look to reach the second round for the first time since 1997.