CLEVELAND -- The box score showed the Toronto Raptors' DeMar DeRozan finishing with just five points on 2-for-11 shooting in the Cleveland Cavaliers' 125-103 Game 2 win Wednesday, but that wasn't enough for J.R. Smith.

He wanted his impact on the defensive end to be truly accounted for.

So when a reporter pointed out after the game that DeRozan did not score a field goal until the third quarter, Smith stepped in to correct him.

J.R. Smith held DeMar DeRozan to just one point -- a technical free throw -- through three quarters of play on Wednesday. Jason Miller/Getty Images

"The fourth," Smith said, knowing full well that by the time he checked out for good at the end of the third, DeRozan had just one point -- on a technical free throw -- and was 0-for-9 from the field.

There was a time in Smith's career when he would play a game like he did Wednesday, when he totaled just six points on 2-for-4 shooting, and feel like he wasn't involved enough.

Even now, prioritizing defense over offense goes against his basic nature as someone whose motto is, when in doubt, shoot.

"He doesn't necessarily get to shoot as much as I think he would like," said Kyrie Irving, "but he's been very locked in from the day we started working on our schemes for the Raptors."

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However, outside of LeBron James' masterful start to the postseason -- which includes averages of 34.2 points on 56.6 percent shooting, 9.2 rebounds, 7.3 assists, 2.7 steals and 1.8 blocks through Cleveland's 6-0 run -- there has been no bigger factor to the team's success than Smith's commitment to defense. And considering that Cavs coach Tyronn Lue said James' production has been triggered by Smith guarding the opponent's best player though the first two rounds, perhaps Smith's defense stands alone as the main catalyst to the Cavs' title defense looking so strong.

"I really challenged J.R., especially with Paul George, of just saying that, 'You have the assignment of guarding Paul George, and we're going to [let] LeBron roam. He's going to guard him throughout the course of the game and the course of the series, but you have the responsibility,'" Lue said. "By doing that, it's given Bron a chance to play extended minutes and being able to roam and play fast and play with a pace. Like I said, you've got to give credit to J.R."

DeRozan averaged 27.3 points on 46.9 percent shooting in the regular season. So far through Cleveland's 2-0 start on Toronto this series, he's averaging just 12 points on 33 percent shooting.

"That's two of the best 2-guards we have, especially in the Eastern Conference, if not the whole league," James said of Smith's task of shifting from George to DeRozan. "He's accepted the challenge. We've tried to just communicate on the back line of defense, second and third of the defense. Just let him know that we're protecting him or what's coming up or what's going on behind him. He's taking the challenge, so we just want to continue to do that.

"J.R. definitely made himself into a two-way player. We said it all last year, said it in the offseason, and because of injuries, he didn't get much of a rhythm for the regular season. But I feel like he's back in form where he left off last year in the postseason."

DeRozan came into the Cavs series averaging 8.3 free throw attempts per game in the playoffs. Smith said his top priority in guarding DeRozan would be to keep him off the stripe, and he has achieved that, helping to hold DeRozan to eight total free throw attempts in the first two games.

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The knock on the Cavs has always been that they need their offense to click in order to generate energy for their defense. But Smith, perhaps the biggest gunner on the Cavs, has been just the opposite.

"With J.R., he said, 'I'm not concerned with the offensive end, I'm going to continue to get stops,'" Lue said. "He's come to timeouts numerous times and said, 'Don't worry about me, I'm going to continue to get stops.'"

Raptors head coach Dwane Casey was asked if Toronto can survive with DeRozan being limited the way he has through the first two games.

"We can't," Casey said. "Honestly, we can't."

Casey also said Cleveland wasn't doing anything "special" in its defensive schemes on DeRozan.

Maybe so. Maybe the traps and blitzes the Cavs are throwing at Toronto's ball handlers aren't wholly unique.

But seeing Smith transform from someone who derives more joy from an opponents' missed shots than his own made shots? That's pretty special.

"J.R.'s been doing a tremendous job," Iman Shumpert said of Smith's defense on DeRozan. "His work's cut out for him this series."