SAN ANTONIO (AP) -- Without another All-Star in an injury-filled season, the San Antonio Silver Stars had a young player make big plays when needed.
Davellyn Whyte had 13 points and seven assists - both career highs - in her second career start in place of injured All-Star Danielle Robinson and the San Antonio Silver Stars held on for a 70-64 victory over Seattle on Sunday.
Shenise Johnson added 17 points and 10 rebounds for the Silver Stars, who snapped the Storm's three-game winning streak.
''Knowing that D-Rob hasn't played a couple games, I know I have to step up,'' said Whyte, in her second season.
''I have been watching her this whole year and filling in whenever she needs a sub. I have to go in there, keep my composure and run the team.''
Whyte had three points, going 3 for 4 on free throws while playing the entire fourth quarter for San Antonio, which is going for its seventh straight postseason berth.
Seattle (13-14) holds a three-game lead over San Antonio (10-17) for the Western Conference's final playoff berth. They have split the regular-season series at 2-all entering their finale Tuesday night.
The Storm are without All-Stars Sue Bird and Lauren Jackson, but the Silver Stars are also missing a pair of All-Stars in Becky Hammon and Sophia Young.
Robinson, who played in her first All-Star game this season, has missed the team's two previous games - both losses.
''Survival of the fittest, definitely,'' Johnson said. ''We are fighting, they are fighting. They are ahead of us in the standings and we are trying to get that tiebreaker against them.''
Danielle Adams and Jia Perkins each had 14 points for San Antonio, which snapped a two-game skid.
Reserve forward Noelle Quinn had 14 points to lead Seattle. Tina Thompson and Camille Little each had 11 points and Temeka Wright added 10 for the Storm.
''The better team won tonight,'' Seattle guard Temeka Johnson said. ''They came out with their business. They came out ready, and we weren't.''
The Storm shot 36 percent from the field and were outrebounded by the smaller, but more aggressive Silver Stars.
After struggling to get their shots off in the first half, Seattle rallied in the second half behind a more aggressive approach.
The Storm pulled within 56-50 with 5 minutes left in the game behind an 8-0 run fueled by a turnover and a steal against the Silver Stars.
''I think that even when we made a couple of runs, they answered with either getting to the free throw line, hitting a couple of big shots, or getting an offensive board,'' Seattle coach Brian Agler said. ''They hurt us on the offensive glass quite a bit. That was the big difference.''
Whyte, Perkins and Johnson closed out the victory, going 7 for 8 on free throws in the final 3 minutes while scoring 11 points. Whyte had an assist on both field goals in that run.
''(Whyte has) got a presence about her, I felt that from the first day she was here,'' San Antonio coach Dan Hughes said.
''I don't think in any of our wildest dreams we thought she would be playing 32 minutes in a key game down the stretch. The girl has got something that says, 'I'm here to play coach.' I like that about her. Now we are leaning on her awfully heavy. Today was a good opportunity to watch her growth a little bit.''
With Quinn, Thompson and Shekinna Stricklen attacking San Antonio's interior defense, Seattle went on an 11-2 run to pull within 48-42 with a minute left in the third quarter. The trio combined for 14 points in the quarter.
Whyte had an assist on each of the Silver Stars' first three baskets as they raced to an 8-0 lead. She added a 3-pointer that gave San Antonio an 11-2 lead.
Robinson missed her second game after straining her right knee at Indiana on Aug. 21.
Seattle only attempted two shots on its first four possessions while committing a shot-clock violation and a turnover.
The Storm struggled to get a shot off against the Silver Stars' aggressive defensive switches, finishing the first quarter 2 for 8. They also failed to get a single offensive rebound in the opening quarter.
''I thought the way we started out in the first quarter dug us a hole a little too big for ourselves,'' Temeka Johnson said. ''It came back to bite us. We need to take that from the game and look forward to Tuesday.''
The Storm's shooting didn't improve greatly in the second quarter, but they did have six offensive rebounds, including four on their third possession.