It was just a week ago that the Nets had lost four of five and were in danger of tumbling down a few rungs in the Eastern Conference standings. But three victories later — including winning both halves of a back-to-back at home against the Wizards on Friday and in Atlanta on Saturday — the Nets begin the second half of a four-games-in-five-days stretch with a chance to give themselves real breathing room in the upper levels of the Eastern Conference playoff chase. “It’s very encouraging,” Nets interim coach P.J. Carlesimo said of his team’s recent play after the easy 93-80 triumph over the Hawks. “But, again, I was the one a couple days ago saying what’s wrong, we have all these losses ... I don’t want to go too far the other way. We’re still day-to-day, but these are two very, very encouraging wins.” With those two wins behind them, the Nets have a pair of below-.500 opponents in front of them in the 76ers tonight and back home against the Hornets tomorrow, winnable games that would allow them to achieve a rare sweep of a four-game-in-five-day segment. It’s important for the Nets to bank away as many wins as they can before they head out on the road for the final two weeks of March, and their strong recent play has opened up significant space between themselves and the teams in the back half of the Eastern Conference playoff race. The combination of the Nets beating the Hawks and the Celtics and Bulls losing yesterday has the Nets holding a two-game lead over the fifth-place Bulls and a 2 1/2 -game lead over the Celtics and Hawks, tied for sixth.