I thought Bellucci would be tough for a rusty John. John had his chances in the 4th and 5th sets to break serve, but Bellucci dug deep and ran Isner around the court in the last two sets, tiring him out. John could barely move by the middle of the 5th set. Bellucci did a good job of holding his nerves after wasting a few break points at 4-3 in the fifth.
I think Querrey will win, but anything is possible at this point