Kazuyoshi Miura scored twice from the penalty spot as the 59-year-old striker became the oldest goalscorer in the history of Japan's longest-running cup competition.
Miura, known as "King Kazu" and now in his 42nd season as a professional, played a key role as third division Fukushima United thrashed non-league Oyama Soccer Club 7-0 in the Emperor's Cup, which is now in its 106th year.
He scored in the qualifying rounds of the competition in late July.
It is the first time Miura has scored more than one goal in a match since he was on target for Australian side Sydney FC in November 2005.
Miura, Japan's first football superstar when the professional J. League launched in the early 1990s, said he practices penalties almost every day after training.
"You never know when it might be your turn," he told reporters after his latest feat on Wednesday.
"That's why I practice them all the time. I'm glad it paid off."
The goals smashed the record for the Emperor's Cup's oldest goalscorer, held by former Japan international Shinji Ono, who was 41 at the time.
Miura started the game as captain and played until he was substituted in the 58th minute.
He stepped up to bury his first spot kick in the 12th minute, then repeated the trick in the 55th after he was brought down in the box.
"There was a unique, quiet atmosphere with none of the opposition fans booing," AFP quoted him as saying.
"I could feel everyone's eyes on me. I'm glad I could put them away in those circumstances."
Miura made his professional debut in 1986 for Brazilian team Santos and has also played in Italy, Croatia, Australia and Portugal.
He made his Japan debut in 1990 but was famously left out of the squad for their first World Cup finals appearance in 1998, despite scoring 55 goals in 89 games for the national side.
He joined Fukushima in January and said he wanted to repay his new team's faith in him with goals and assists.
