neck_and_neck
1. [ adjective ] inconclusive as to outcome; close or just even in a race or comparison or competition
Synonyms: nip_and_tuck head-to-head
Examples:

"as they approached the finish line they were neck and neck" "the election was a nip and tuck affair"

Related terms: inconclusive
2. [ adverb ] even or close in a race or competition or comparison
Synonyms: nip_and_tuck head-to-head
Examples:

"the horses ran neck and neck" "he won nip and tuck"

Related terms: head-to-head