Cessna Citation CE-525 Captain reported landing safely after the left engine flamed out at FL330. The engine re-lit on its own during troubleshooting procedures.

Narrative

Filed Altitude FL 410Incident Occurred while descending from FL 410 to join ZZZZZ Arrival. We had leveled off at FL 370 prior with no issue; then flameout at FL 330.At approximately XA:00 on Day 0 the crew of Aircraft X experienced a #1 (left engine) flameout. From the best of both of our recollections; it occurred as we leveled off at 33;000 feet and and were pushing thrust levers forward to maintain airspeed. (No icing condition) First indication of an issue was the #1 Generator Off Light and associated Warning/Caution light. Second; left engine oil pressure warning came on prompting us to look at the N1; N2 and ITT (Interstage Turbine Temperature) gauges showing 0 ITT and turbine spin down. We requested priority handling immediately due to the need to get to our drift down altitude and began looking for the closest suitable airfield to land and requested ZZZ. Once established on a vectors and descent profile; PM broke out the checklist and began running it. At an altitude neither of us remembers; we opened the checklist to the next section and began discussing the procedures and next steps. PF began slowing the aircraft to get within the 200 KIAS limit for restart. We then ran through the checklist to attempt to restart Engine 1 which was unsuccessful and Start did not occur; so we aborted the start. PM was distracted for what seemed like no more than one minute and before I could go back to the first checklist section; the engine re-lit on it's own at an altitude we don't remember and appeared to be functioning normally; we didn't increase power as we were in a continuous descent. We continued descent for Runway XX at ZZZ; descending though icing conditions at 12;000 MSL which we turned engines and wings on for; until clear. #1 Engine continued to appear normal all the way to final and we made the decision to make a two engine approach with PM ready to adjust flaps in the event the engine failed again. Due to the strong gusting winds at ZZZ; we determined a dual engine approach would be safest in these conditions; with the PM closely monitoring engine function to touchdown. Landing was uneventful and we taxied to the FBO without further incident.