SAN ANTONIO — Even Walt Frazier thought Jalen Brunson was done, cooked, out of Game 1 of the NBA Finals for keeps.Yes, the same Frazier who once watched the New York Knicks’ captain, Willis Reed, hobble out the Game 7 tunnel in Madison Square Garden, with one leg all torn up, and used that source of inspiration to torch the Los Angeles Lakers with 36 points and 19 assists to win the 1970 NBA championship.Yes, that same guy thought the current Knicks captain was calling it a night before playing even one full quarter of his first career finals game.“He had his poor shooting and he was hobbling around, went to the locker room. I counted him out, man,” Frazier told The Athletic. “I thought, ‘He’s not coming back.’ And all of a sudden he got a second wind.“That’s why he’s the reigning Mr. Clutch. And that’s why this team is where they are.”That’s why the Knicks erased a 14-point third-quarter deficit Wednesday night and beat the San Antonio Spurs 105-95 for their 12th consecutive postseason victory, tied for the second-longest streak in NBA history with the 1999 Spurs, who beat the Knicks the last time they reached the finals.Dressed in all his sartorial splendor, the 81-year-old Frazier, immortal point guard of the immortal Knicks title teams of ’70 and ’73, stood in the bowels of Frost Bank Center in awe of his team’s incumbent 29-year-old point guard. Brunson limped out of the game late in the first quarter after teammate Landry Shamet blasted San Antonio’s Harrison Barnes into his right knee. The Knicks staffers around Brunson on his hobble to the locker room looked about as concerned as Frazier sounded.Brunson returned only to have the Spurs’ Luke Kornet step on his left ankle in the middle of the second quarter, after the Knicks’ superstar crash-landed on a made basket. From his rump on the baseline, Brunson waved in frustration at referee Scott Foster. Soon enough, a captain who screams at refs about as often as another New York captain, Derek Jeter, used to scream at umps, was seen angrily shouting at Foster, “That’s a f—ing foul.”