TOWSON, Md. — The rain came and the floodgates opened.

The top-seeded United States unleashed a six-goal barrage in a downpour at Unitas Stadium, turning a slim early margin into a comfortable lead in an 18-3 victory over ninth-seeded Japan in the World Lacrosse Women’s Championship quarterfinals Wednesday night.

The U.S. will play Australia in the first of two nationally televised semifinals Thursday at 7 p.m. Eastern on ESPN2. Canada and England follow at 7 p.m.

“They’re physical. They’re aggressive. They have a lot of energy, and they have a lot of great players,” U.S. midfielder Marie McCool said of Australia. “Hannah Nielsen is a legend.”

McCool did a little bit of everything Wednesday. She had two goals, an assist and three draw controls to earn Player of the Match honors.

For a team that’s done a lot of dancing in the dorms, on the bus and walking to the stadium, the tropical weather did nothing to dampen its spirit.

Megan Douty especially had a spring in her step. The U.S. defender injured her hamstring in the opener against Canada and had not played before returning to the lineup Tuesday against Hong Kong. She looked spry as ever playing extended minutes for the first time in the tournament Wednesday.

“I would be lying if I said I didn’t want to be on the field. Coaches are going to call it cautiously. I’m feeling a hundred percent,” Douty said. “I want to compete and be out on the field just like anyone else here.”

Douty’s return makes whole a U.S. defense that’s often overlooked considering the team’s offensive firepower. Becca Block, Alice Mercer and Emma Trenchard have played the majority of minutes with Douty out. The Americans have allowed just 4.83 goals per game and have not let an opponent reach double figures since their 16-11 win over Canada opening night.

Block, Douty and Mercer all played on the gold medal-winning 2017 U.S. team.

“We’re just so in sync,” Douty said. “And Emma fits right in the mold with how we play.”

McCool was happy to see Douty back on the field.

“She’s such a huge piece of this team. She’s been a part of the U.S. women’s national team program for quite some time. She’s one of our leaders,” McCool said. “She looked good as new out there. We’re excited to have her back for the most important part of this tournament.”

Eight different players scored for the U.S., led by attacker Kayla Treanor, who had four goals and two assists. Treanor got the rock star treatment after the game, with several Japanese players taking turns getting photos with her. Monica Jones was in tears. “You guys are so good,” Treanor said.

The top-scoring team in the tournament, Japan came in averaging 18 goals per game. It certainly looked the part of spoiler in the early going. Jones’ putback pulled Japan within 3-2 with 3:47 left in the first quarter.

But Treanor converted a free position at the 1:31 mark and the U.S. went on a six-goal binge to put the game out of reach.

U.S. attacker Charlotte North, who had two goals overturned in a first-round win over Hong Kong due to stick violations, scored three goals and added two assists — with no stick intrigue. Attacker Sam Apuzzo also had a hat trick.

Midfielders Ally Mastroianni (seven draw controls) and Taylor Cummings (five) led the U.S. to an 18-8 advantage on draws.

Kokora Nakazawa (Louisville), whose performance Treanor acknowledged specifically when the teams exchanged comments at midfield, led Japan with two goals in the loss.