The Red Sox kept waiting for Mike Mussina to make a mistake. It was an agonizing wait.

“During the first six innings, he kind of put on a clinic,” said Boston manager Terry Francona before Game 2 last night against the Yankees. “He was throwing different speeds, different pitches, up, down nothing was over the middle of the plate. Everything was on the black.

“With a six-run lead he was very, very tough,” said Francona. “And obviously we didn’t do anything. He was efficient, he didn’t change speeds and didn’t throw anything over the middle.”

For 61/3 innings Tuesday night in Game 1, Mussina flirted with baseball immortality. Nineteen Red Sox came to the plate. Nineteen returned the Boston dugout, several of them muttering.

Mixing a revitalized fastball with a nasty knuckle-curve, Mussina took his perfect-game bid into the seventh. He struck out Johnny Damon leading off, his eighth strikeout of the game.

Then Mussina made his first mistake. He left a belt-high pitch over the middle of the plate. Mark Bellhorn drove it to left-center and Mussina’s dance with perfection was over.

“Sure, you’re going to think about it,” said Mussina. “You’re only human. I know what’s going on, but you got to keep after it.”

Bellhorn’s double seemed to take the edge off Mussina. He allowed four runs on four hits before Joe Torre came to the mound. The Red Sox got back seven of eight runs, but then Bernie Williams slammed a two-run double that assured the Yankees of the 10-7 win.

“Those were the best six innings I’ve thrown all year,” Mussina said. “I went out and was able to focus on what I wanted to do. Stuff, location, curveball – they were all good. And I kept throwing hard.”