James Harden scores 23 points, grabs 15 rebounds and hands out 10 assists in the Rockets' 115-104 victory over the Mavericks. (1:05)

HOUSTON -- There was so much joy on the Houston Rockets on Sunday afternoon.

They had James Harden waving his towel as he ran onto the floor during the middle of a fourth-quarter burst, with a cheesy smile on his face.

They had Jason Terry making a corner 3[pointer and then running down the court, arms out as if he was a jet flying through clear skies.

They had a loud Sunday afternoon Toyota Center crowd, chest bumps from players and smiles in a noisy locker room afterward.

Yes the Rockets have a modest two-game win streak, the latest coming 115-104 over the Dallas Mavericks. The Rockets took over the game with a 65-point second half, part of a rally from an 11-point, third-quarter deficit.

Interim boss J.B. Bickerstaff coached his you-know-what off, sticking with a small lineup and utilizing the skills of newly acquired Josh Smith, who improves this team with his sharp passes and ability to play strong defense.

Josh Smith, James Harden and the Rockets were all smiles on Sunday, as they beat the Mavericks 115-104 AP Photo/Bob Levey

The Rockets are not the team GM Daryl Morey expected them to be, title contenders, just yet. After a weekend sweep of the Milwaukee Bucks (Friday) and the Dallas Mavericks (Sunday), a visit to the New Orleans Pelicans on Monday night doesn’t seem like the daunting task it would have been earlier in the season.

“I think for the most part we were just trying to figure it out,” said Trevor Ariza, who had his best game of the season, a season-high 29 points on 11-of-15 shooting from the floor. “We’re looking at what we did last year and trying to figure out how to get back to that. That was no fun. Putting the pieces back to help us get to where we were, bringing Josh back in definitely helped us out a lot.”

At the start of the fourth quarter, Bickerstaff kept Ty Lawson, Corey Brewer, Terry, Ariza and Smith on the floor. The Mavericks held a one-point advantage until things took off for the Rockets. The ensuing 17-4 run ended when Smith faked out Dirk Nowitzki in the paint with his version of The Dream Shake, the move Hakeem Olajuwon employed when he was dominating the NBA, to make a hook shot and push the lead to 103-91.

“I’m just trying to contribute, man,” Smith said.

Harden contributed, too, with a controlled fury during a fast-paced game. But sometimes it appears he’s not enjoying himself. The season has worn on a few people around this Rockets group, where grumpy might be the best word to describe things. This was probably the happiest we’ve seen Harden all season.

“Yeah, I am, I think we are all,” he said. “Guys are getting open shots. Trevor is getting open shots that he and Brew and Jet were normally getting [last season]. You get good shots, you get easy shots and the entire game changes and the fun is definitely back.”

When his afternoon was over, Harden finished with a triple-double, his second of the season: a nifty 23-point, 15-rebound and 10-assist night. Harden even had two blocks to go along with him being plus-10 in the box score.

Of course, Smith has been the undisputed champ around this place the past 48 hours. Smith scored a season-high 16 points, blocked two shots, had two steals and added two assists.

There is something about Smith that brings the best out of the Rockets. His ability to pass, especially from the post, helps, along with his desire to guard anybody at any position.

It gives Bickerstaff options, something all coaches want.

“He’s a guy, again, because of his ability to pass the ball, he’s a guy that brings everybody together,” Bickerstaff said. “He can do that because he can make all the passes, he can make all the plays. Then his courage to shoot the ball late when he’s missed a few, most guys would turn those down and since we’ve seen him and he’s been with us, he’s thrived in those situations.”

When the Rockets are passing the ball and helping each other, a better team shows up. There were 27 assists, tying for the fourth most this season, 44 points in the paint, Bickerstaff using Patrick Beverley and Lawson at guard to close the show and the defense holding the Mavs to just 19 points in the fourth quarter.

When you have positive plays working for you, people are having fun.

“You got to play the game to help everybody out,” Lawson said. “When you’re definitely touching the ball and more involved everybody feels like they can do a little extra.”