Following a jury trial, defendant was convicted of selling cocaine in violation of the Georgia Controlled Substances Act. Defendant's motion for a new trial was denied and he appeals. In his sole enumeration of error, defendant asserts the evidence was insufficient to enable a rational trier of fact to convict defendant beyond a reasonable doubt. Held:

An undercover policeman testified that defendant sold him a substance which was subsequently identified as cocaine. Although defendant denied he sold the substance to the undercover agent, the testimony of the agent, standing alone, was sufficient to authorize a conviction. Fredericks v. State, 172 Ga. App. 379, 380 (1) (323 SE2d 265). Moreover, contrary to defendant's contention, the State demonstrated with reasonable certainty that the cocaine introduced into evidence was the substance which defendant sold to the undercover agent. Sea Boyer v. State, 178 Ga. App. 372, 373 (1) (343 SE2d 146). The evidence was sufficient to meet the standard of proof required by Jackson v. Virginia, 443 U. S. 307 (99 SC 2781, 61 LE2d 560).