Siri Mullinix swatted away two penalty kicks and the Washington Freedom advanced to its second successive Founders Cup, overcoming host Boston in a shootout following a scoreless draw in Saturday's WUSA semifinal opener.

Maren Meinert — playing her final WUSA contest — fired high with the first kick of the tiebreaker, and Mullinix stopped weak shots by Kristine Lilly on the Breakers' second attempt and Heather Aldama on the fourth to send the Freedom into next weekend's championship game in San Diego.

Washington, which lost to Carolina in the 2002 title game, will meet the winner of Sunday's Atlanta-San Diego semifinal in the Aug. 25 Founders Cup III at Torero Stadium.

All three Freedom shooters connected in the shootout, with Jennifer Meier, Jacqui Little and Mia Hamm going to the left to beat Breakers goalkeeper Karina LeBlanc. Only Dagny Mellgren converted for Boston, the first WUSA regular-season champion not to advance to the final.

''Before the PK competition, I told [my teammates] to make all theirs, because I thought I was going to save at least one,'' Mullinix said. ''They did their job and made it easy on me.''

Some 9,070 at Nickerson Field witnessed a tight, tense clash, one featuring frequent shifts in momentum, that reached penalties following superb performances by both goalkeepers, Boston's back line and Washington's Carrie Moore, Sandra Minnert and Hamm.

Washington played deeper in the back, leaving Mellgren no space to sprint behind the defense, and Boston found it difficult to create strong chances from their advantages with possession. All the Breakers' best opportunities arrived in the final 13 minutes. Aldama fired wide in the 80th minute. Washington keeper Siri Mullinix tipped a well-placed Hucles shot from off and over the crossbar in the 85th and cut off Mellgren from a ball in front in the 89th.

Little made the biggest stop, three minutes into stoppage time. Mellgren got her head to an Aldama corner kick, bouncing it toward the left post, and Little — stationed at the post — chested the ball away.

Washington, usually through Hamm or Abby Wambach, were more consistent in testing the Breakers, but goalkeeper Karina LeBlanc needed to make only two saves, both on Wambach.

On the first, in the 35th minute, LeBlanc got her foot to a Wambach shot after a poor headed backpass from Chrisy McCann left the Freedom forward 1-on-1 with the keeper. She stopped Wambach's point-blank header in the 99th minute to preserve the shutout, and twice won battles with Wambach for crosses in front of Boston's net.

The result officially is a tie, so Boston extends its unbeaten streak to 11 games while the Freedom head to the title game winless in three matches.

The match was the fourth in WUSA history to go to overtime and the second to be decided by penalty kicks. Atlanta beat Philadelphia, 3-2, on Cindy Parlow's 101st-minute goal in a 2001 semifinal, and the then-Bay Area CyberRays toppled the Beat on PKs following a 3-3 tie the following week in the first Founders Cup. Carolina beat Atlanta on Carla Overbeck's 92nd-minute goal in a semifinal last year.

SATURDAY'S SUMMARY

Aug. 16 at Boston

Boston 0 Washington 0. Goals: None.

Boston — LeBlanc; Kluegel, Sobrero, McCann, Aldama; Hucles; Mugneret-Beghe, Monroe (Hawkins, 75), Lilly; Mellgren, Meinert.

Washington — Mullinix; S. Little, Moore, Grubb, Minnert; Jones, Stoecker (Zimny, 68); Golebiowski (Meier, 58); Hamm; J. Little, Wambach.

Yellow cards — Boston: Kluegel 56; Washington: Wambach 43.

Penalty kicks — Boston: Meinert-high, Lilly-saved, Mellgren-Goal, Aldama-saved; Washington: Meier-Goal, J. Little-Goal, Hamm-Goal.

Referee — Misail Tsapos.

A — 9,070.

WUSA PLAYOFFS
Semifinals
Saturday, Aug. 16
Boston 0 Washington 0.
(Washington advances, 3-1, on penalties.)

Sunday, Aug. 17
San Diego at Atlanta, 6 p.m. (ESPN2)

Founders Cup III
Sunday, Aug. 24
Washington vs. San Diego or Atlanta at Torero Stadium (San Diego), 4 p.m. (ESPN2)

All times Eastern