Catalyzes an unusual C-C bond hydrolysis of 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid (HOPDA) to produce benzoic acid and 2-hydroxy-2,4-pentadienoic acid (HPD). 2,6-dioxo-6-phenylhexa-3-enoate + H2O = 2-oxopent-4-enoate + benzoate + H(+) Inhibited by 3-Cl HOPDA. Xenobiotic degradation; biphenyl degradation; 2-hydroxy-2,4-pentadienoate and benzoate from biphenyl: step 4/4. Homodimer. Belongs to the AB hydrolase superfamily. BphD family.