Brandi Chastain, wearing a U.S. Julie Johnston No. 19 jersey, eagerly waited her turn for an autograph from the emerging American the World Cup star helped develop right up the street at Santa Clara University.

The 23-year-old Johnston offers a rare combination: She's a central defender with a knack for finding the net. Johnston returned to her old college stomping grounds and scored another goal for the Americans in their lead up to the Women's World Cup next month in Canada.

She connected on a leaping one-touch goal off Lauren Holiday's corner in the 54th minute of a 3-0 victory against Ireland on Sunday in a send-off match for the Americans. It was her third goal in three games.

"She's scoring more goals than some of our forwards are scoring," fellow defender Ali Krieger said. "She has probably has more goals than she does on her club or even me, and I've been here six or seven years. I'm super jealous of that, but she's great at attacking those set pieces. That's what her job is. She's there to score when we need it, and I think those are going to win us games in the World Cup. She's off to a great start."

Johnston keeps making good on her opportunities on both ends of the field, and has landed herself a key role on coach Jill Ellis' 23-woman roster. Johnston grabbed the job after initially earning more playing time when Christie Rampone and Whitney Engen were injured in March at the Algarve Cup in Portugal.

"She's a weapon. She's so good in the air," Ellis said. "She's so committed on her run because she gets to that post every time. She'll run through anything. She's been a great add on for us."

Johnston's three goals in three games have all come on set plays. Her mother, Kristi, flew in to see this one on Mother's Day in the sellout crowd of 18,000 at the MLS San Jose Earthquakes' new state-of-the-art Avaya Stadium. In fact, Johnston figures she had a couple hundred people she knew in the stands — many of whom she heard calling her name.

"To be able to score and have such a great start to the send-off games is truly special, for sure," Johnston said. "It's pretty remarkable. But the services I'm getting are perfect. I'm always happy to finish them when I can. I'm just enjoying it."

She scored her first career goal for the Americans in a 2-0 win over France in the Algarve Cup final March 11. She scored two goals with a game-winner in her rookie season for the Chicago Red Stars last year.

When Ireland's Katie McCabe dribbled into the 18-yard box in the 81st minute Sunday, Johnston quickly took the ball away and cleared it.

Playing just her 10th match for the national team, Johnston downplayed the idea that nobody expects the defenders to score on this team featuring big-name stars such as Alex Morgan and Abby Wambach, who scored two first-half goals less than 3 minutes apart.

"We do," she said. "We sure do. Our defenders take it on us, we don't want goals but if we can score them for us, in the air or not, we'll do that."

Johnston shared several moments on social media from her trip back to the Bay Area. Her college is only about a mile away.

"Can't come to San Jose without stopping by my second home," she posted with a photo from Santa Clara's Leavey Center. She also wrote, "San Jose! So happy to be back" with a smiley face emoji.

The new-look U.S. defense with Johnston in the middle and Meghan Klingenberg playing one of the back spots is using these exhibition games to perfect its communication and experiment with different combinations for the last line of defense in front of goalkeeper Hope Solo.

"Julie's a warrior back there," midfielder Carli Lloyd said. "Even though she's one of the younger players, she's not afraid to communicate and offer guidance back there. She's taken her opportunity and seized it. She's got a good momentum going into her first major tournament with this team. She's a great asset back there."

Klingenberg switched from the left to the right side to start the second half. She scored the Americans' first goal in a 4-0 win against New Zealand on April 4 in St. Louis.

Johnston will try to extend her scoring streak next Sunday against Mexico in Carson.

"Julie has scored goals from set pieces, but what she does exceptionally well and better than most players in the world is that she's got great anticipation," Chastain said. "She understands how the game moves and reads it better than anybody. Physically is her gift is she has incredible lateral agility. She can wait on a play and then spring into action and get to a ball that others just can't."

Even Johnston's teammates are left in awe.

"I mean, she's like our secret weapon," Klingenberg said.