By Steve Ginsburg

MIAMI (Reuters) - LeBron James and the Miami Heat began their summer vacation Monday after receiving a formidable lesson on fourth-quarter play by the Dallas Mavericks.

While the Heat struggled to establish a rhythm down in the fourth quarter of close games, Dallas excelled with the game on the line and won the best-of-seven NBA Finals 4-2.

"The Heat had a chance to sweep the series and failed to execute down the stretch of games repeatedly," Hall of Fame NBA coach Jack Ramsay told Reuters on Monday.

"Give the Mavs credit -- they never gave up even when they were behind by double digits. They hung in the game. They made the plays down the stretch and won the series."

Dallas won the 31-year-old franchise's first championship on Sunday after beating host Miami 105-95 before 20,000 of the Heat hopeful at the American Airlines Arena.

While series MVP Dirk Nowitzki gritted his teeth with the game on the line, the Heat, especially James, looked passive and played poorly.

"From games two through five, in the final four-and-a-half minutes of the game, the Heat shot five for 27 and had nine turnovers. That tells the story."


Ramsay said it was not a new scenario.

"It was a problem that plagued the Heat during the regular season," he said. "They had a stretch where they could not win a game in the last couple of minutes.

"They found a way to bungle their offense and let their defense come apart. This was not a new characteristic for the Heat.

"It's something they're going to have to overcome if they're ever going to win a championship."

"Look, Miami's time is going to come," he said. "Their talent is undeniable. At some point it's going to carry the day. There's no doubt about that.

"But their time is not now. Our time is now. It needed to be now. They had a great phrase, "Now is the time for us, and it was. It had to be."

"LeBron has been a lightning rod for a lot of everything," he said. "Criticism and a lot of the noise that's been created outside. It's really unfair.

"He made a tremendous sacrifice to come here, and he's been an ultimate team player. He should not be criticised for that.

"Sometimes there's no excuses, there's no blame, sometimes you just simply come up short. And the competition you're playing against sometimes plays better."

Ramsay said the Heat will eventually lift the Larry O'Brien championship trophy.

"They're going to win a championship one of these years," said Ramsay, an NBA analyst with ESPN. "(Heat president) Pat Riley will maneuver the roster and add some positive pieces.

"But in the final analysis it will be up to Wade and James to put this team on their respective backs and bring them home in the critical games."

(Editing by Frank Pingue)