BOSTON (Reuters) - The Boston Celtics opened up a 2-0 lead in their playoff against Cleveland on Thursday while defending champions San Antonio clawed their way back into their series with New Orleans after a 110-99 win.

Boston earned a comfortable 89-73 home win over the Cavaliers, who now badly need victory in Saturday's Game three in Cleveland if they are to have any hope of halting the Celtics.

Paul Pierce, who scored 19 points, said that all season the team had been looking to be dominant at home.

"When we get the crowd in the game and we are flowing and our adrenaline is flowing .... it's tough to beat us here. We feed off everything they bring us every night," he said.

"It was a total team effort and this is the way we want to play each and every night. We kept our turnovers down, we rebounded the ball, made the extra pass, and we got the job done defensively and that is true Celtics basketball right there."

Boston's Ray Allen, who had not scored in seven quarters, claimed 16 points while Cleveland's LeBron James scored 21.

The San Antonio Spurs could ill-afford a third defeat to the Hornets and they had Argentine Manu Ginobili and Tony Parker to thank for the win, both scoring 31 points.

New Orleans held a slight lead at half-time but the Spurs surged forward desperately and the pressure paid off.

"We are happy that we got the win, that's the main thing," said Parker.

"The next one is going to be tough but we were more aggressive this time and did a good job to contain them."

The Spurs will look to level the series in San Antonio on Sunday.

(Reporting by Simon Evans; Editing by Peter Rutherford)