"It's just the beginning," he said. "We've got bigger goals than this."
Harden scored 28 points, Terrence Jones had 10 of his 15 points in the fourth quarter, and the Rockets beat the Dallas Mavericks, 103-94, on Tuesday night to get out of the first round and exorcise any bad feelings that lingered from last year's opening-round loss to Portland.
Houston won the Western Conference series 4-1 to advance to face the winner of the Clippers-San Antonio Spurs series in the second round.
"We've worked extremely hard through a lot of adversity through the season," said Rockets center Dwight Howard, who missed half the season with injuries. "To make it to the next round is big, but the job is not complete."
The Rockets bounced back from a lackluster performance in a 121-109 loss in Game 4 to head to the West semifinals for the first time since Yao Ming starred for Houston.
Howard had 18 points and 19 rebounds to help the Rockets dominate inside and Josh Smith scored 20 points. The Mavericks couldn't get going from long-range, making only five of 26 three-point shots.
Monta Ellis led Dallas with 25 points and Dirk Nowitzki added 22.
"It just felt like every time we were right there we didn't get enough breaks to really make it a game," Nowitzki said.
Said Mavericks center Tyson Chandler: "We dug ourselves in a hole by falling down 0-3. It was an uphill battle from there."