This report presents the successful experience intravenous thrombolysis (IVT) with tenecteplase (Nektelisa, Generium, Russia) for ischemic stroke (IS) therapy at the Regional Vascular Center of the Komi Republican Clinical Hospital. Specifically, it demonstrates the first clinical case in the Russian Federation of successful tenecteplase use for wake-up stroke (WUS) based on DWI/FLAIR mismatch criteria on MRI. Current clinical guidelines support IVT with alteplase for WUS based on MRI DWI/FLAIR mismatch. However, global data on tenecteplase application using these criteria are limited, and such cases have not been previously described In Russia. We present a successful IVT with tenecteplase in a patient with severe ischemic stroke (NIHSS –18) 8.5 hours after the time last known well. Following a single bolus administration, a significant regression of neurological symptoms was observed within the first hour; the NIHSS score decreased to 7 points 10 hours post-thrombolysis. A control CT scan at 24 hours ruled out intracranial hemorrhage, and no therapy-related complications were recorded. At discharge on day 15 (NIHSS –4), the modified Rankin Scale (mRS) score=3, indicating a significant regression of functional deficit. This case demonstrates that tenecteplase administration for wake-up stroke beyond the 4.5-hour window, based on DWI/FLAIR mismatch criteria, is safe and effective. This first successful experience with tenecteplase in the Russian Federation provides an important basis for the implementation of the Nektelisa into clinical practice, including for patient categories with an extended therapeutic window, provided strict adherence to proven selection criteria is maintained.