LeBron James, Evan Turner

Cleveland Cavaliers' LeBron James (23) defends Boston Celtics' Evan Turner in the first quarter of a first round NBA playoff basketball game, Sunday, April 19, 2015, in Cleveland.

(AP Photo/Mark Duncan)

CLEVELAND, Ohio -- Everybody is tough until taking a punch square to the jaw, just like every team is confident until being easily discarded in a playoff game. The Boston Celtics have been focused, resilient and hopeful for months.

But after dropping Game 1 to the Cleveland Cavaliers, 113-100, their spirit will be tested more than ever. So, apparently, will their defense, which was used as a canvas for art.

Over the days leading up to the playoffs, the Celtics vowed they would not be overcome by the moment, swore they would treat the postseason like "another game." They respect LeBron James, they just think they can beat him. It's what everybody says but the Celtics pointed back at the last two months as proof. We trust in each other, they said. We believe we can give ourselves a chance.

For a quarter-plus, they provided evidence to support their optimistic theory. Tyler Zeller pitched in some buckets. Kelly Olynyk got aggressive. Isaiah Thomas darted into the paint. The Celtics spread the court, drove closeouts and built an eight-point lead. Uneasiness hung in Quicken Loans Arena like a morning fog. But the first half did not just show what Boston can accomplish when it executes the game plan relentlessly. It also illustrated exactly how difficult the Celtics' task is.

Over a span of 27 seconds, the Cavaliers cut a seven-point deficit to one, and then they surged ahead. Even when they missed, Tristan Thompson, Kevin Love and Timofey Mozgov pursued offensive rebounds, sometimes beating several Celtics to the ball. There is simplicity to Cleveland's offense, but there is also a daring edge. Kyrie Irving (30 points) cannot make incredible shots without first determining to take them. He had 20 points in the first half, LeBron James (20 points, seven assists, six rebounds) made plays when he wanted to, and Love (19 points, 12 rebounds, four assists) made himself useful even before finding his shot. James did not deliver his most powerful effort, but he did not need to. He received more than enough help.

When the game turned: Early in the second quarter, Marcus Smart hit a free throw to take a 38-31 lead. To that point, the Celtics had knocked down 58.3 percent of their shots, including 4 of 6 from downtown. Olynyk had 10 points on 4-for-4 shooting. The offense was flowing and the defense was not bad enough to prove destructive.

But Cleveland took flight. Over the last 9:30 of the second quarter, Irving had 12 points on all threes, Love and James took turns feeding each other with perfect outlet passes, and the Celtics were outscored 31-17. On the last play of the quarter, Irving crossed over Evan Turner, pulled up with a hand close to his face, and drilled yet another triple.

The Cavaliers continued their dominance into the third quarter, ultimately opening a 20-point lead. Though Celtics replied with a 14-0 run -- they are a resilient bunch -- any momentum turned to ashes when, again, Cleveland threw flames from behind the arc.

Celtics star of the game: Thomas, who announced himself to the playoffs with 22 points, 10 assists and five rebounds. Shooting 47 percent, hitting 8 of 22 from deep and putting six players in double figures, the Celtics showed they can score against Cleveland. Now, they need devise a way to grab a lot more rebounds and limit the NBA's most star-studded offense.