It was hosts Empoli who were off to a better start in the first half, galvanised by recent results and the form of their attacking players.
The Azzurri forwards frustrated Toro's defensive midfielders (Adam Masina and Samuel Coco were immediately cautioned), then Lorenzo Colombo began his personal duel of shots from distance against Vanja Milinkovic-Savic, who was also good at repelling Faustino Anjorin's attempt.
It took the visiting team a while to garner a threat and they did so in the second half with two headers, one from ex-Samuele Ricci and one from Antonio Sanabria, prodigiously repelled for a corner by Johan Vasquez.
Then the two coaches resorted to changes to unlock the match and Vanoli got it right: in the 64th minute the Varese coach inserted Adams for Antonio Sanabria and six minutes later the Scottish striker opened the scoring with a goal from midfield, a sudden shot on which the Empolese goalkeeper could do nothing about.
The ex-Southampton striker could have doubled shortly afterwards but failed to do so from two paces after a good move by Borna Sosa.
The hosts threw themselves forward but were unable to come up with anything dangerous, leaving Toro to claim a crucial three points on Friday.