St. John's, which lost to Hofstra by 17 points earlier in the week, last started 1-4 in the 1922-23 season.
Duke (5-1) didn't have its "A" game following a 22-point win at No. 5 Michigan State on Wednesday night, but the Blue Devils didn't really need it as St. John's self-destructed in the second half.
The Red Storm cut a 15-point first-half deficit to eight with 12½ minutes left before falling apart with poor shot selection and shoddy ballhandling.
Daryll Hill missed a 3-pointer and a pull-up shot and the Red Storm turned it over on three straight possessions over a two-minute span to end any hopes of another upset over the Blue Devils.
St. John's pulled off a late-season surprise by beating Duke 72-71 last March in Madison Square Garden.
Randolph, who put on 35 pounds of muscle in the offseason, was the key player in Duke's 14-4 surge to go up 65-47 with 8:10 left.
The 6-foot-10 center started the run with two free throws and added two more from the foul line and two follow shots as Duke won its 30th straight at Cameron Indoor Stadium.
Meanwhile, Dockery finished with a career-high 12 points on 5-for-6 shooting. His previous best was 10 against Ohio State last season as a freshman.
Hill led the Red Storm, who turned the ball over 21 times, with 17 points.
Duke opened a working margin with an 11-0 run midway through the first half. Five players scored in the spurt to give the Blue Devils a 23-9 lead with 9½ minutes left.
The closest St. John's could get the rest of the half was 39-28 at the break.