Celtics head back to LA in driver’s seat

“This was huge for us, let’s be honest,’’ said Celtics coach Doc Rivers. “We knew we had to win this game going into it.’’

And they did, despite 38 points by a scoring machine named Kobe Bryant.

There’ll be no more basketball at the Causeway Street Gym in the spring of 2010. If we see the Celtics again in Boston, they’ll be on Duck Boats, accompanied by Mayor Menino citing the franchise’s golden history of Bill “The Stilt’’ Russell, the Hick from French Wyc, Maxwell’s Coffee, and Dohnny Most’s famous call of “Varitek Stole the Ball!’’

The Garden’s last loud roar of June was impressive. The NBA Finals, by definition, draw a high-roller crowd, but folks who packed the big barn last night were loud and loyal. They were, dare we say, like a Game 7 Bruins crowd. The sellout included Hub sports royalty Bill Belichick, Tedy Bruschi, Jonathan Papelbon, and John Havlicek. That’s a lot of hardware lining the perimeter of the parquet.

History holds that when an NBA Finals series is 2-2, the winner of Game 5 wins the championship 76 percent (19 of 25) of the time. The Celtics have never lost a seventh game in the Finals. They have been in this event 20 times, winning 17, including nine series against the Lakers. Boston has won a championship against the Lakers in five buildings: the Minneapolis Auditorium, the old Boston Garden, the Los Angeles Arena, the Los Angeles Forum, and the new Boston Garden. Now the Celtics have a chance to win the championship at the big arena on Figueroa Street in downtown LA.

Pierce came out gunning in Game 5, connecting on 7 of 10 shots in the first half as the Celtics ran to a 45-39 lead at intermission. The Lakers shot only 33 percent (14 for 42) in the first two quarters. LA’s last lead of the game was 37-36.

Pierce stayed hot in the third quarter, canning a three to make it 50-39 in the first minute after halftime.

“We didn’t want to go into LA down three games to two, so this was the biggest game of the year,’’ said Pierce.

It was an odd night for the captain. He seemed to be pouting at times and walked away in mid-play at the end of the second quarter.