Carl Baker was instrumental for the Sky Blues, who scored five goals in a game for the first time since April 2008. He opened the scoring with a low drive in off the post after 51 minutes and seven minutes later turned superbly in the area to volley home.
In between, a penalty from David McGoldrick in the 53rd minute made it 2-0. Frank Moussa capitalised on a lightning-quick counter-attack to finish well after 75 minutes, before substitute Adam Barton completed the rout in the 79th minute, drilling in from 16 yards.
Robins said: "I thought we were quiet first-half at times, we tested the water while creating one or two openings and we passed it around well. Then in the second half we stepped it up and the goals came. I'm delighted - it's more like what we want to see.
"Going in front like we did was positive. The full-backs got forward and that's important in attacking. Injuries meant we could change it around and bring Gary McSheffrey in and I thought he was more like the player he can be.
"Second-half we switched things around and Frank Moussa was outstanding in the middle. Adam Barton then came on and delivered a great strike for a goal with his first touch and it was a good day all around. We won't get carried away - I just liked it and everyone went away happy."