The right-back headed home in the first half to give Chesterfield a fourth straight win, while Crewe slipped into bottom four.
Chesterfield had a great chance in the 10th minute, but Gboly Ariyibi’s close-range shot was saved by Crewe goalkeeper Paul Rachubka and Gary Roberts’ follow-up was blocked in the six-yard box.
The home side were almost caught on the break in the 20th minute, but Uche Ikpeazu fired straight at Chesterfield goalkeeper Tommy Lee, who had to save at the feet of Lauri Dalla Valle two minutes later.
But Chesterfield went ahead in the 26th minute when Roberts’ clever chip to the back post was headed by Darikwa over Rachubka, who was beaten again in the 38th minute by Roberts but his shot was deflected behind.
Jay O’Shea was denied by the woodwork in the 74th minute when his shot came back off a post and Sam Clucas had a shot deflected over as Chesterfield dominated to run out deserved winners.