From every angle, this was a night the Mavericks needed to devote their full attention to laying down their best effort. Coming off two losses, and with a challenging road trip in front of them, their meeting with New Orleans on Monday was as close to a must-win in March as you can get. Lose and they would have been closer in the loss column to the lottery than they would have been to the No. 2 seed in the Western Conference. As it turned out, they needed only one half of forceful basketball to dig out a 103-92 victory over the Pelicans. It was the Mavericks’ 40th victory of the season against 22 losses. They became the sixth team in the NBA to reach the 40-win mark. The Pelicans brought in a five-game winning streak, but they had played Sunday night in Denver. The Mavericks are face a rugged back-to-back Thursday and Friday at Portland and Golden State, and they knew they needed to have a sense of urgency. “We haven’t been playing very well,” coach Rick Carlisle said. “So it’s important to just keep at it. In the second half, the guys really stuck together and made a stand.” Carlisle liked the fact that six players scored 14 or more points. But he singled out Bernard James, who started for Tyson Chandler, as a strong contributor. “He was plus-23 and didn’t score a point,” Carlisle said. “He does a lot of good things at both ends. It’s more than noteworthy. We need guys that can step in like he did tonight in the absence of Tyson.”