Shimabukuro and Safiullin traded holds through a tense 49 minute set, Safiullin clinching the tiebreak after 12 games of relentless serve-holding.
Safiullin broke for 2-0 but Shimabukuro broke for 1-2 and again for 3-2, then held for 6-4 to seize control with two decisive breaks.
Shimabukuro broke for 3-2 and held for 6-4 saving both break points, clinching the set after Safiullin's sole resistance a 5 minute hold for 1-1 saving one.