Nakashima saved two break points in a hold for 5-5 and won the tiebreak, surviving a 52 minute set of unbroken serve until the decider.
Medjedović won the tiebreak for 7-6, matching Nakashima's resilience through another set of alternating holds that forced a second decider.
Nakashima broke for 1-0 and again for 4-1 after Medjedović saved three of four break points, then held for 6-2 to clinch the match.