New York ? Take that, big sis!

Serena Williams confirmed at the U.S. Open what’s become clear since spring: She’s not just No. 1 in the world, she’s No. 1 in her home.

Unabashed about powering the ball and taking advantage of mistakes just as against any other opponent, she easily beat Venus Williams 6-4, 6-3 Saturday night to win a third straight Grand Slam title all by defeating her older sister in the final.

“Venus dominated me for a long time, but we always stayed close,” Serena said. “Family comes first for us.”

When it ended, they hugged and kissed at the net, both smiling. They were given a standing ovation by the record crowd of 23,164.

Between the lines, Serena showed little love for Venus, taking full advantage of her 10 double faults and 23 other unforced errors.

Venus had won 19 straight matches, owns a tour-leading seven titles and is 60-3 against everyone but her sister in 2002. She’ll still have to settle, for now, for being No. 2, the spot she was relegated to by Serena after Wimbledon.

“I just had a great year,” said the 22-year-old Venus, who’s 15 months older. “More than any person other than Serena could ask for, I guess.”

The men’s final today promises to be a classic: Pete Sampras vs. Andre Agassi.

A matchup Agassi called “a nice toast to the past” pits a generation’s best server 31-year-old Sampras against its best returner 32-year-old Agassi and the winner will be the Open’s oldest champion since 1970.

Agassi beat defending champion Lleyton Hewitt 6-4, 7-6 (5), 6-7 (1), 6-2. Sampras, without a title in more than two years, beat Sjeng Schalken 7-6 (6), 7-6 (4), 6-2.