Juve, winners of the last nine titles, were 10 points behind Milan at kick-off after the Rossoneri beat Bologna 2-1.
Second-placed Inter Milan can reduce the gap at the summit to two points when they host Benevento at 19:45 GMT.
Italy winger Chiesa, who joined from Fiorentina in October, struck at close range from Alvaro Morata’s pass in the 20th minute as the visitors dominated the first half.
The result made it four straight wins in all competitions for Juventus – who set up a tantalising Coppa Italia semi-final against Inter by beating SPAL 4-0 in midweek. The first leg of that tie takes place at Inter on Tuesday (19:45 GMT).