Dallas ? The Dallas Mavericks have lost their scoring touch and appear tired, a sign that all the running and all of the games might be taking a toll.

The Mavericks are feeling the lingering effects of an extended first round as much as playing the first four games of their Western Conference series against Sacramento over six days.

The semifinal series is tied at 2-all after the Kings won, 99-83, Sunday night. That game began 22 hours after the Mavericks took the series lead with a 141-137 double-overtime victory.

“The Kings did a great job with their backs against the wall,” Dallas guard Steve Nash said. “We’ve had a tough schedule lately, going seven in the first round. They had more energy than us.”

Game 5 is tonight in Dallas.

The Mavs’ 83 points Sunday matched their record first-half scoring total in a 132-110 win in Game 2. Dirk Nowitzki, Michael Finley and Nash — who combined for 103 points in Game 2 and 116 in Game 3 — shot just 16-for-55 for 38 points.

“It was frustrating out there for all of us,” said Nowitzki, held to 11 points before being ejected with two minutes left after two technical fouls, the second for kicking a pile of towels. “We were a step slower defensively. Offensively, we had no legs and every jumper looked short.”

The Mavericks returned home Monday, an off day and a much-needed chance to rest. They will go right back to Sacramento Wednesday, their fourth trip to the West Coast this postseason.

“Going back and forth to the West Coast, and then jumping right into the Sac series is always a daunting task,” Nash said.

Dallas was pushed to seven games in the first round against Portland, requiring two back-and-forth trips, while Sacramento needed just five games to get past Utah. The Kings got five days off between series; the Mavericks got one.

The Kings proved they could win without scoring leader Chris Webber, who tore cartilage in his left knee Thursday during Game 2. Then again, Sacramento never doubted that.

“We have always felt confident, even losing Chris,” Kings coach Rick Adelman said. “We felt that we have the type of people that can step up and win. Our team does not lack confidence. We understand we lost our best player, we also understand if everybody steps up we have a chance to beat anybody.”

Webber — the Kings’ scoring and rebounding leader — is putting off surgery, hoping to possibly play again this season if the Kings can advance to the NBA Finals.

“If we play like we did (Sunday) in Dallas, we’ll do it again,” Kings guard Mike Bibby said. “We’ve always had the confidence. The only thing that’s going to take it away from us is ourselves.”

Dallas was eliminated by the Kings in Game 5 of the second round last season. So, this series has been extended by at least one game.

The Mavericks have the extra game at home if the series goes the distance, but their focus is on tonight.

“We know it is going to be an intense battle for 48 minutes, but we are going in with the intention that we need this win,” Finley said. “We are going to go in and do whatever it takes to get the win. If it takes four overtimes, we are going to do that as well.”