That span was fleeting.
The Rockets (52-14) rebounded in short order, produced eight third-quarter 3-pointers, and ultimately rolled to a 23-point victory despite Harden being sidelined by a sore left knee.
Harden is expected to return to the starting lineup on Monday when Houston hosts the San Antonio Spurs (37-29) at Toyota Center.
The Rockets own a two-game lead in the loss column over the Golden State Warriors in the chase for home-court advantage in the postseason.
Not only were the Rockets without Harden, they were missing Ryan Anderson (hip), Nene (rest) and Brandan Wright (knee). Houston has been hamstrung by injuries for lengthy stretches this season, but like they did in Dallas, the Rockets have mastered performing short-handed.
"We've been dealing with it all season," said Rockets guard Eric Gordon, who filled in for Harden and scored a game-high 26 points while sinking 6 of 11 3-pointers.
"We've just got to play collectively as a group. We played very good defense and offensively ... we really got it going in the second half. We just played really good basketball."
Houston clinched a postseason berth with the victory. Doing so was a forgone conclusion, and it was an accomplishment that is one part of a larger objective.
"I'd much rather have the No. 1 seed," Gordon said. "We've still got 16 games left. We just want to finish No. 1. That's really the main goal."
Having qualified for the playoffs in each of the past 20 seasons, the Spurs are slumping and their impressive streak is in jeopardy. San Antonio has dropped five of seven games since the All-Star break and 10 of 12 overall to drop to seventh in the Western Conference.
The Spurs will enter Monday just one-half game ahead of a three-way tie for eighth, with the Los Angeles Clippers (36-29) currently holding the tiebreaker over the Denver Nuggets and the Utah Jazz (both 37-30).
Since the break, the Spurs have been a middling both offensively and defensively relative to efficiency, and their effective field goal percentage (50.7) would rank 26th in the league if extrapolated over the entire season.
Published reports have All-NBA forward Kawhi Leonard returning Thursday against the New Orleans Pelicans. Leonard has played in just nine games this season and has been out since mid-January as he continues to manage a right quad injury.
But even that bit of potential good news was tempered by Spurs coach Gregg Popovich.
"Well, that's good for them," Popovich told the San Antonio Express-News about the report. "I'm glad they're reporting that. ... I don't worry about reports."
To complicate matters, San Antonio will be without LaMarcus Aldridge (right knee soreness), Manu Ginobili (rest) and Leonard at Houston.
The Spurs have already clinched their first road losing record since 1996-97 and are in danger of producing fewer than 50 wins for the first time in 19 seasons.
After so many campaigns of incredible success, the Spurs appear vulnerable.