AUGUSTA, Ga. — As Tiger Woods stood in the 13th fairway waiting to hit, over his right shoulder came a wild, unbridled cheer. Woods turned to look in the direction of the sound, toward the 14th green, where he knew Phil Mickelson was playing. He put his right hand on his hip, his shoulders slumping ever so slightly as he looked at his feet.

This is Woods’s 16th Masters, and he knows how to read a roar in the small valley beneath the Augusta National clubhouse. The clamor he heard was too euphoric, too laden with surprising joy to have been for a simple birdie. Woods immediately suspected that Mickelson, who had just eagled the par-5 13th hole, had done it again on the par-4 14th.

“At that point, I knew guys were running away from me,” Woods said later. “I was seven shots back, I was behind four or five guys. I knew there was still time left, but I had to do something to stay with them.”

At a Masters that has been part soap opera, part athletic event and part stage show, Woods, the lead character in all of it, did enough in the next hour to remain in the drama. Woods did not play spectacularly, but he immediately and emphatically improved on the erratic golf he had exhibited over the first 12 holes.