Experts said Andrejczyk has suddenly installed herself as the early gold medal favourite for the upcoming Tokyo Olympics.
Her over-71-metre feat at the European Throwing Cup in Split, Croatia, on Sunday, was also the third best result in the history of women's javelin.
The 25-year-old Pole's previous personal best, which was also the Polish record, was a throw of 67.11 metres at the Olympic Games in Rio de Janeiro in 2016.
“I don’t think right now about the world record. I think about the hard work I need to do before the Olympics” in Tokyo, Andrejczyk was cited as saying by the european-athletics.com website.
The Czech Republic's Barbora Špotáková holds the world record in the women's javelin with a throw of 72.28 metres.
The European Throwing Cup is an annual competition for athletes specialising in the javelin, discus, hammer and shot put.