Jakob Ingebrigtsen sets new European record at Silesia Diamond League
He followed the field until the final lap, when he sprinted clear, beating the previous record by 0.81 seconds set in Oslo last month.
He fell short of the world record of 3:26:00, set by Morocco's Hicham El Guerrouj 25 years ago in Rome, by over a second.
Kenya's Abel Kipsang (26) finished second, crossing the line almost two seconds after Ingebrigtsen in 3:29.11.
Akani Simbine (29) of South Africa grabbed his second Diamond League 100m win in a row, clocking 9.97 seconds, with the first four separated by just 0.02 seconds. American Fred Kerley (28) took second place, experiencing his first defeat of the season.
"I know I am the first to beat Fred this year, we have a good friendship, a good rivalry. I am very satisfied with my performance and hope to continue my good form," Simbine said.
Kerley appeared unaffected by the loss.
"I feel good about today's race. Nothing was missing. I got my job done."
American Sha'Carri Richardson (23) won the women's 100m, with a time of 10.76 seconds. She edged out Jamaica's Shericka Jackson (29) by 0.02 seconds, securing her second 100m Diamond League win of the year.
"I love the time. I put a great race together. This was a great competition, it was amazing. I executed correctly," Richardson said.
Yulimar Rojas (27) from Venezuela set a new world lead of 15.18m to win the women's triple jump.
Poland's Natalia Kaczmarek (25) gave the home crowd something to cheer when she comfortably won the women's 400m with a personal best time of 49.48.
"Things looked good in training, but I was not quite able to translate it into competition. Now things finally worked out," Kaczmarek said.
Favourite and world record-holder Armand Duplantis (23) cleared 6.01m to win the men's pole vault ahead of American Sam Kendricks (30).