Jakob Ingebrigtsen obliterated the 28-year-old 3,000m world record by more than three seconds before Armand Duplantis broke his own pole vault world record at the Diamond League meeting in Silesia.
Norway's Ingebrigtsen looked in disbelief as he crossed the finish line in seven minutes 17.55 seconds, breaking the previous record of 7:20.67 set by Kenya's Daniel Komen in 1996.
Komen's time had been the longest-standing men's athletics world record in an individual track event.
In the pole vault, Sweden's Duplantis cleared 6.26m, one centimetre higher than his previous best set as he won Olympic gold in Paris earlier this month.
His second-attempt clearance on Sunday was the third time the 24-year-old has broken the world record this season, and his 10th overall.
Duplantis was joined by American Sam Kendricks and Greece's Emmanouil Karalis - who won Olympic silver and bronze respectively - in jumping 6m.
"This year I focused on the Olympics, the record just came naturally because I was in good shape," Duplantis said.
"So I am not surprised with the record today, but I am thankful."
Ingebrigtsen wants to challenge 'all world records'
Earlier this week, Ingebrigtsen had exacted a modicum of revenge over American Cole Hocker by winning the 1500m at the Diamond League meeting in Lausanne.
The Norwegian lost his Olympic title over the distance to Hocker at Paris 2024, with Great Britain's Josh Kerr second, but won 5,000m gold.
The 23-year-old carried that form into Sunday's meet in Poland, although admitted he did not expect his world record time.
"It feels special, amazing. I was hoping to challenge the world record here, but based on my training, I can never predict exactly what kind of time I am capable of," he said.
"I would not have imagined I could run 7:17, though. At the beginning the pace felt really fast, but then I started to feel my way into the race and found a good rhythm.
"Now I want to challenge world records at all distances, but it is one step at a time."
Olympic 10,000m silver medallist Berihu Aregawi was second behind Ingebrigtsen in 7:21.28 - the third-fastest time in history - while fellow Ethiopian Yomif Kejelcha placed third (7:28.44).
Reekie is GB's top performer
Great Britain's Daryll Neita finished fourth in the women's 100m final in 11.01 seconds, which was an improvement on seventh in the Lausanne meet three days ago.
After running a season's-best 10.88 to win Thursday's race, Dina Asher-Smith opted not to compete in Silesia after saying on social media her body needed a "little rest".
Jamaica's Tia Clayton won in 10.83.
Jemma Reekie was second in the women's 1,000m in 2:32.56, behind Kenya's Nelly Chepchirchir, while Georgia Bell finished third in the women's 1500m.
Kenya's Olympic champion Emmanuel Wanyonyi targeted the men's 800m world record after narrowly missing out earlier in the week, but was beaten by Canada's world champion Marco Arop (1:41.86).
Jamaica's Rasheed Broadbell upset new Olympic champion Grant Holloway in the men's 110m hurdles in Lausanne but the American hit back by edging victory in 13.04.
Botswana's Olympic champion Letsile Tebogo claimed his second Diamond League win in four days, clocking 19.83 in the 200m.
Olympic bronze medallist Fred Kerley won the men's 100m in 9.87, with Paris silver medallist Kishane Thompson sitting out even though he had been due to run.
Femke Bol and Karsten Warholm missed out on gold in Paris but won the women's and men's 400m hurdles in Silesia - in 52.13 and 46.95 respectively.