However, deep into injury time England Under-20 winger Miles Benjamin caused panic in the Wasps defence and when the hosts went off their feet at the resulting ruck Crichton stepped up to leave Wasps struggling just one place off the foot of the table.
Bourgoin were ruled to be off their feet at the ruck shortly after the restart and Steenson stroked home his penalty from 30m out to give Exeter a 9-5 lead.