MIAMI, Florida (AFP) – LeBron James and the Miami Heat put the final touches on their second round playoff series with a dramatic fourth quarter finish and are now ready for an even bigger challenge.

Miami on Wednesday advanced to the NBA playoff semifinals, defeating the Boston Celtics 97-87 with the help of some clutch late baskets from James and a team-high 34 points by Dwyane Wade.

Miami took advantage of three turnovers and five missed shots in the final five minutes by the Celtics to score the last 16 points of the fourth quarter and win the series four games to one.

Wade finished with 34 points, 10 rebounds and five assists, while James had 33 points and Chris Bosh added 14 points and 11 rebounds.

“You can never take foot off gas because they make you fight for everything,” James said. “They are the reason why all three of us came together, that blueprint they had. They are a great team.”

Miami will next play the winner of the Chicago and Atlanta series. The Bulls lead that series, 3-2.

It marks the first time the Heat are in the NBA semi-finals since they won the league championship five years ago.

James, who put Miami up for good with a three-pointer with 2:10 remaining, and Bosh are in their first season with the Heat. After a slow start, the move to bring the two stars together with Wade in Florida seems to be working.

In Oklahoma, Kevin Durant scored 19 points and Daequan Cook came off the bench to make 18 as the Oklahoma City Thunder beat the Memphis Grizzlies 99-72 in the fifth game of their playoff series.

The resounding win Wednesday gives the Thunder a 3-2 series lead, marking the first time they have led the second round best-of-seven NBA playoff.

“We played great defence. Everyone was in tune, locked in,” Durant said. “It was a group effort.”

The Grizzlies will try to level the series in game six on Friday.

Russell Westbrook finished with 11 points and six assists while five other Thunder players reached at least nine points.