Falk, a 21-year-old defender out of Stanford, beat Freedom goalie Brianna Scurry to Japanese national team star Aya Miyama's free kick and scored only six minutes into the opener.
"It was a great ball from Aya," said Falk. "I just went for it - I didn't think I was going to get to it, but I did and it went in. It was a very surreal experience ... very exciting."
Abily, signed from French club Lyon, put the game away with a nifty chip over Washington goalie Brianna Scurry after being sprung down the right side by Marta.
The closest Washington came to scoring was on a shot by Lori Lindsey that hit the near post in the second half.
"We are really happy with the victory," said Sol coach Abner Rogers. "To open up the inaugural season and come out with a victory is very pleasing. There were times when we played very well, but fitness was a bit of an issue for both teams, as you could see. It is only going to get better. I was definitely happy. We dodged a few bullets; even though we came out with a good victory, it was very beneficial."
March 29 in Carson, Calif.
Los Angeles 2 Washington 0. Goals: Falk (Miyama) 6, Abily (Marta) 87.
Los Angeles - LeBlanc, Fletcher (Larkin, 46) Falk, Boxx, Cox, Miyama, Bock, Abily, Makoski, Duan (Welsh, 84) Marta.
Washington -Scurry, Whitehill, Janss, Singer, Sauerbrunn, Lindsey (Gibeau, 72), Bompastor, Long, Sawa, Wambach, Zimmeck (De Vanna, 43).
Referee: Kari Seitz.