Blankenship scored from two yards out the put the Bobcats (2-1) up 31-17 early in the fourth.
The Thundering Herd (2-1) came right back as Rakeem Cato threw a 38-yard touchdown to Gator Hoskins, then forced Ohio to punt on the ensuing drive, but Cato was intercepted by Devin Bass on the next play.
Following a field goal by Ohio, Cato rushed for a touchdown to cut the deficit to three, but the following onside kick was recovered by the Bobcats to seal the game.
Tettleton was 25-for-38 with a touchdown and Matt Waters had 83 yards on six receptions.
Cato finished 30 of 44 for 367 yards for Marshall.
Tommy Shuler caught 9 passes for 95 yards receiving while Hoskins had 81.
Oregon's Pharaoh Brown once faced amputation for a horrific leg injury. But he's come all the way back and starred in Oregon's spring game.
Watch some of the top plays from former Southern Miss cornerback Kalan Reed.
Watch some of the top plays from former Illinois safety Clayton Fejedelum.
Watch some of the top plays from former Clemson wide receiver Charone Peake.
Watch some of the top plays from former UCLA wide receiver Devin Fuller.
Watch some of the top plays from former Western Michigan tight end Daniel Braverman.