Antwerp, Belgium ? Venus Williams won her first title of the season, and a pattern is becoming clear: Just about the only person who can beat her is her sister.

Williams defeated Kim Clijsters 6-2, 6-4 Sunday to win the Diamond Games for the second straight year, completing the tournament without losing a set.

Williams is ranked second in the world, and her overpowering serve and nearly flawless backcourt game were too much for the third-ranked Clijsters. Williams’ serves reached nearly 118 mph; Clijsters’ serves hit 93 mph.

“I put a lot of pressure with my serve,” Williams said. “I was always able to force the point.”

Since July, 2001, Williams has lost only 10 times. Five of those losses were to sister Serena, including defeats in the final of the last four Grand Slams. Clijsters inflicted two losses during the stretch, but Williams was clearly the better player Sunday, even with the Belgian playing before a home crowd.

“She was simply far too strong on the important points,” Clijsters said. “Her first serves made a lot of difference.”

If Williams wins the Diamond Games in any of the next three years, she can claim the diamond-encrusted trophy racket worth $1.07 million, which goes to the first triple champion in any five-year span.

Asked whether she would return to defend her title, Williams said, “I have no choice.”

Williams welcomed challenges to her title, even one from her sister.

“If you want to challenge me here, Serena, if you are watching, come on,” she said.