"It comes down to a two-game winning streak for the Miami Heat.

Or a lost season.

Failing to capitalize in their return to AmericanAirlines Arena, the Heat fell 94-90 Tuesday night to the Boston Celtics, now down 3-2 in these best-of-seven Eastern Conference finals.

"It's a loss and that's all it is," Heat coach Erik Spoelstra said. "And that's what our focus is right now, to fight any noise from outside and any conditions."

The conditions certainly aren't favorable.

The Heat know they don't have history on their side: Teams that have won Game 5 of best-of-seven NBA series tied 2-2 had gone on to win 83.5 percent of such series (137-27). The Celtics entered 8-0 in Game 5 of such situations in their Big Three era.

"This is what the playoffs are all about," Spoelstra said of his team's all-or-nothing predicament. "It tests your collective character and your resolve.""