Christian Pulisic scored a hat trick as the American announced his arrival in the English Premier League by powering Chelsea to a 4-2 win over Burnley on Saturday.
The win extended a seven-game winning run for Chelsea's young squad and strengthened its hold on a Champions League spot in fourth.
"It's a very special day for me," Pulisic said in televised comments. "I'm happy with the progress I've made."
Making his first league start since August, Pulisic seized the opportunity with a superb solo goal in the 21st minute — his first goal at Chelsea.
Pulisic snatched the ball off defender Matthew Lowton near the halfway line and charged forward, beating James Tarkowski with a stepover before striking the ball low into the far corner.
The American attacking midfielder, who arrived in the summer for 64 million euros ($71 million) from Borussia Dortmund, made it 2-0 in the 45th with similar swagger. Pulisic ran at the defense, going past Tarkowski again and hitting a shot which took a deflection off Ben Mee.
Pulisic completed his hat trick with a header off Mason Mount's cross in the 56th.
It was the second hat trick by a U.S. player in league history after Clint Dempsey scored three in Fulham's 5-2 defeat of Newcastle in 2012.
After Pulisic's third goal, Willian added a fourth two minutes later on a counterattack.
Burnley's late goals from Jay Rodriguez and Dwight McNeil gave faint hope of a comeback.
After the final whistle, Pulisic applauded the traveling fans as he left the field dribbling the match ball.
"I'm really happy for him," Chelsea defender Fikayo Tomori said of Pulisic. "He's opened his account and with a hat trick as well."
Since last month's loss to Liverpool, Chelsea has won four straight league games and seven in all competitions.
"It's important that we keep our feet on the ground," Chelsea coach Frank Lampard said.