According to Wikipedia
There is dramatic evidence for allosaur attacks on Stegosaurus, including an Allosaurus tail vertebra with a partially healed puncture wound that fits a Stegosaurus tail spike, and a Stegosaurus neck plate with a U-shaped wound that correlates well with an Allosaurus snout.
Citation #86 is
Carpenter, Kenneth; Sanders, Frank; McWhinney, Lorrie A.; and Wood, Lowell (2005). "Evidence for predator-prey relationships: Examples for Allosaurus and Stegosaurus". In Carpenter, Kenneth (ed.). The Carnivorous Dinosaurs. Bloomington and Indianapolis: Indiana University Press. pp. 325–350. ISBN 978-0-253-34539-4.
The Black Hills Institute appear to be selling a Camarasaurus sp. Tibia with Bite Marks - Fossil Replica of which they say
Camarasaurus was a long-necked (sauropodmorph) dinosaur that lived during the Jurassic age. Camarasaurus reached lengths of 60 feet (18 m) and weighed up to 18 tons (16 tonnes)! One end of this ‘teething bone’ has been completely removed by predation, probably a feeding or teething Allosaurus.