Backstrom’s OT goal puts Washington one win away from advancing.
Bobrovsky made 54 saves for Columbus, which hosts games 3 and 4 of first round series.
Game 2 set for Sunday in Washington.
Detroit finishes with 30 wins, fewest in non-strike season since 1985-86.
Detroit has lost 15 of 19; will finish season at home against Islanders Saturday.
Larkin, Athanasiou score in Detroit’s third straight win.
Six different players score for Detroit.