Auburn police Commander Mike Hiram said an officer spotted the car getting onto Highway 18 just before midnight.
The officer followed while waiting for backup and turned on his lights and siren after the suspected thieves merged onto southbound I-5 near the Federal Way truck scales.
The driver of the stolen car sped off, reaching speeds of 100 mph, Hiram said.
As officers were backing off the chase in Fife, the driver lost control while changing lanes and rolled the car over. Both men were ejected from the car.
Medics took the two men to a local hospital where they were listed in critical condition. No one else was hurt, but another car did sustain some damage from flying debris, Hiram said.
The southbound lanes of the freeway were closed for several hours through the night for the crash investigation but reopened around 5 a.m.