An irate McDonald’s customer with a sugar rush stabbed a rival in Midtown following a dispute over the amount of sweetener in his morning coffee, police said Wednesday.

The 57-year-old victim was eating inside the McDonald’s on Eighth Ave. near W. 35th St. about 8:20 a.m. Tuesday when the suspect complained his coffee was too sweet, cops said.

An argument erupted between the two customers and spilled outside the fast food joint, where the suspect pulled a blade and stabbed the victim in the chest, officials said.

EMS took the victim to an area hospital where he was treated for a minor injury.

It was not immediately clear why the victim was targeted by the accused stabber. Police were uncertain if the victim gave the suspect his coffee, or if the victim tried to intervene after the suspect began complaining.

The suspected stabber, described as a bearded man with glasses carrying several tote bags, ran off and was still being sought Wednesday. Police released surveillance images of the suspect in the hopes that someone recognizes him.

Midtown has seen a startling 151% jump in assaults this year, NYPD data shows. As of Sunday, 329 attacks have been reported to cops in Midtown South. Last year, only 131 assaults had been reported during the same period.

Shootings in the area have also jumped, from just one last year to eight this year.

Anyone with information regarding this incident is urged to call NYPD Crime Stoppers at (800) 577-TIPS. All calls will be kept confidential.