A technique for performing deduplication extends a match found in a digest database by looking forward and/or backward to adjacent data elements. The technique performs data comparisons between data blocks adjacent to a candidate block and corresponding data blocks adjacent to an identified target block. If the data comparisons indicate that an adjacent candidate block matches an adjacent target block, then the adjacent candidate block may be deduplicated to the adjacent target block without having to compute a hash value of the adjacent candidate block or to perform a separate lookup into the digest database.