Seike’s hat-trick, as well as a goal from fellow debutant Kirby from the penalty spot, capped off an enjoyable afternoon in Crawley.
Fans were on their feet applauding when her third goal flew into the corner and the 28-year-old was lifted into the air by team-mate Jorelyn Carabali.
Seike, who became the first player in WSL history to score a hat-trick on her debut in the competition, celebrated with Brighton’s players at full-time after realising she could keep the match ball when handed it by the officials.
“She’s a fantastic player and you could see when she first came in what type of player she is,” said Kirby, who left Chelsea in the summer. “She is direct, wants to get into the box and wants to score goals.
“You need those players if you are going to score goals in this league. We’re really happy to have her and I’m delighted for her.
“You can see her qualities from a mile away and it’s fantastic to play with.”
Seike had a strong relationship with Kirby down Brighton’s right-hand side and it’s an area Vidosic hopes her side will exploit more in the future.
“If you don’t shoot, you don’t score,” added Kirby. “It’s not always going to come off, but today everything she hit went into the corner.
“When she’s running one-v-one, I’m lucky. I can just give it to her and she will do something with it. If she keeps scoring goals like that, I’m sure everyone will be very happy with her.”