Sophia Young scored 20 of her 26 points in the second half and the San Antonio Silver Stars improved to 4-0 for the first time in franchise history, overcoming a 14-point halftime deficit to beat the Phoenix Mercury 101-99 Friday night.
Becky Hammon added 22 points and nine assists, and rookie Danielle Adams had 16 points and six rebounds for the Silver Stars, the last unbeaten team in the WNBA.
Diana Taurasi had 20 points, five rebounds and three assists for the Mercury (0-3).
Phoenix missed two shots after getting the ball with 23 seconds left and trailing 98-96. Jia Perkins hit one free throw and Becky Hammon hit two more in the final 4 seconds to give San Antonio a 101-96 lead with 2.4 seconds remaining. Kara Braxton hit a 3-pointer at the buzzer for the final margin.
Candice Dupree had 18 points and 12 rebounds, and Penny Taylor added 18 points and 10 assists for the Mercury, one of two winless WNBA teams.
Hammon put the Silver Stars up 98-94 with a driving layup with 47.3 seconds left, but her layup attempt with 23.5 seconds to go went out of bounds, giving Phoenix the ball. Phoenix's DaWanna Bonner missed a short shot and Dupree missed the put-back. Bonner fouled Perkins with 4 seconds left.
Phoenix turned nine San Antonio turnovers into 16 first-half points and built a 51-35 lead late in the second quarter. The Mercury only made three miscues in the first 20 minutes and made five of their first six shots from beyond the arc.
But Young scored 12 points in the third quarter, 10 in the first 4 minutes, for San Antonio. Danielle Robinson hit four free throws in the final 46 seconds of the third to trail 76-74.