BOSTON -- Celtics assistant coach Lawrence Frank, the man in charge of all things defense on a Boston team that tops the league in points allowed per game, was incredulous.
Boston opened the second half with Rajon Rondo applying full-court pressure as Miami's LeBron James brought the ball up the floor, creating what should have been an exploitable matchup for the Heat. As he recounted the story of the bench chatter at that moment, Celtics head coach Doc Rivers even threw in some of Frank's high-pitched inflection (often audible on TV broadcasts) when relating that his top assistant was screaming, "We can't do this!"
Rivers, on the other hand, soon decided it was crazy enough to work.
"I [told Frank], 'You're right, but we're just going to keep doing it,'" said Rivers, who was rewarded when the Celtics outscored the Heat by 16 over the first 5:15 of the second half and held on for an 85-82 triumph in a Sunday showdown at TD Garden.
Rondo produced his seventh career regular-season triple-double with 11 points, 10 assists and 10 rebounds over 43:06 of court time. But it was his defensive effort, particularly the pressure against James, that turned the game around for Boston.
"It was Rondo's idea," Rivers said. "I told him to pressure the ball, and he took that as whoever brought it up. I didn't mean that. He took it that way and I stayed with it. Actually, during a timeout, he thought we were going to switch back, and when I didn't say anything, he was surprised. Because I liked it.
"Sometimes you go off the books, and today was clearly that. That matchup made no sense, honestly. And it hurt us a couple of times. The only thing I saw, honestly, was that it gave us life."
For a Boston team down to essentially seven available players (10 dressed, but Nate Robinson was limited by a bruised right knee, rookie Avery Bradley barely got off the bench and fellow rookie Luke Harangody earned a DNP), that life translated into a dizzying 20-4 run to open the second half, transforming a four-point halftime deficit into a game-high 13-point advantage (one that Boston would need all of in the end).
Rondo was an absolute pest during the opening minutes of the third quarter. He got to the line (drawing three fouls to help put Boston in the bonus early), made a trio of shots and dished out a couple of assists. He finished the period, in which Boston outscored Miami 35-18, with 9 points, 4 rebounds and 3 assists (enough to overlook four missed free throws).
All the while, he blanketed James, bumping and clutching him even while the Heat superstar was simply trying to receive an inbounds pass. All told, the Celtics held LeBron to 5 points in the quarter.
"I actually thought it was great," Celtics center Kendrick Perkins said. "We know what Rondo is capable of doing. He turned it up another notch. I've never seen anybody make LeBron turn his back to the basket. He didn't really want to put it on the ground around him. I thought that was huge. When he picked [James] up, the energy just picked up and the guys kind of backed him up after that."
The Celtics backed Rondo up in more ways than one. After Rondo got flattened by a Zydrunas Ilgauskas screen during the third-quarter run, Kevin Garnett responded at the other end by crumpling Mike Miller with a (legal) screen of his own. Dwyane Wade took exception and delivered a stiff arm to Garnett's mug, leading to a dust-up (and a flagrant 1 on Wade).
While referees sorted things out, Rondo sneaked into the Heat huddle, attaching himself to James' hip yet again. James twice pushed Boston's lanky point guard out of the huddle before Ray Allen and the referees cleared him out (possibly with his safety in mind).
"I think I was pretty poised and kept my composure," Rondo said with a shrug. "I was just trying to see the play. Nobody called a timeout. They drew the play up on the court and I wasn't trying to start anything. I thought I could get my head in there and look at the play they were drawing up."
Forget the huddle, Rondo was already in the Heat's heads. With Miami unable to convert offensively, Boston kept pushing the pace, culminating with a driving layup by Rondo that put the Celtics out front 59-46 with 6:45 to play in the third. Miami called timeout and as Boston players headed for the bench, Garnett waited at midcourt to deliver a low-five to Boston's spark plug.
"Whenever you see Rondo doing that, we call that pressing up," Garnett said of Rondo's ball pressure. "When he's pressing up like that, it just totally ignites the defense. I not only come up, Ray gets a little more aggressive, Perk is aggressive, Paul [Pierce] is aggressive -- it totally sets the tone. He definitely sets that and now we have something to say: 'Hey look, this is what we're doing, let's continue to press on.'"
While Rondo tried hard to stick to the company line that this win meant no more than any other, he couldn't help but suggest that it did. Not just because it vaulted Boston back to the top of the Eastern Conference standings, leapfrogging Miami, but because Boston had dropped three of its past four and needed a little confidence boost in the face of mounting injuries.
And, yes, beating the team that many pundits picked to steal Boston's conference crown, and doing so for the third time in three meetings this season, was decidedly sweet.
"We needed this game," Rondo said. "We didn't want to lose three in a row. We've got to protect home court and, obviously, I think we're happy about the win. It's a big game for us."
Big enough that Frank might not lose it if his point guard applies similar full-court pressure in the near future.
Chris Forsberg covers the Celtics for ESPNBoston.com. Follow him on Twitter.