Kipyegon, a two-time Olympic 1500m gold medallist and twice world champion, clocked 4min 07.64sec for victory and another world best after setting world records in the 1500m and 5,000m in June.
Her time over the mile obliterated the previous world record of 4:12.33 set by Ethiopian-born Dutch runner Sifan Hassan in 2019, also in Monaco.
Aided not only by on-the-mark pace-setting but also by the Wavelight trackside lighting system that indicated world record pace, Kipyegon took the lead with two laps to run and made no mistake in perfect running conditions with a temperature of 30 degrees Celsius (86 Fahrenheit).
"I really enjoyed the race. I came for that, I wanted to chase the world record," said Kipyegon. "It was amazing. And just before the world championships" in Budapest in August. [...] The time was really good because the race was well planned. It just went smoothly and to accomplish the world record – that is amazing. "What will be the next – I do not know [...] I do not know how I am doing this because it just keeps going really in a good way. I was feeling healthy and just focusing myself for this world record.
The athlete gave birth to daughter Alyn in June 2018 and shed 19kg on the road back to competition.
Kipyegon admitted that a trio of world records in quick succession had not been her objective coming into this year, but confirmed she would go for double gold in Budapest.
"When I started this season, my goal was to just break the world record in the 1500m. It was still in my head and in my mind," said the 29-year-old Kenyan who set world records in the 1500m in Florence on June 2, followed by another record over 5,000m in Paris a week later. "I want to defend my world title at 1500m in Hungary but I am going to double also with 5,000m in Budapest."
In a blistering race there were national records for Ireland (Ciara Mageean, second) and Britain (Laura Muir, fourth).
New regional records were set for Oceania (Australian Jessica Hull, fifth), North America (American Nikki Hiltz, sixth) and South America (Venezuelan Joselyn Brea, 11th).
Ethiopia's Olympic 1500m silver medallist Freweyni Hailu finished third in the race.
"It was a blessing to do this with these ladies," said Kipyegon, who was enveloped by the rest of the field after smashing Hassan's record. "I can see that they are all happy for me and it is so emotional. It is a blessing, it just does not happen every time you run."