A penalty in first-half stoppage time condemned us to defeat in the UEFA Youth League in France on Tuesday.
Ayanda Sishuba converted from 12 yards for Lens after we had rarely looked in danger during the opening 45 minutes.
Mehmet Ali was without injured duo Ethan Nwaneri and Myles Lewis-Skelly, and his under-19 side lacked a cutting edge, despite enjoying plenty of possession.
It means we head to Sevilla on Matchday 3 still searching for our first point in the group, having lost our opening game 2-1 at home to PSV Eindhoven.
Behind at the break
In front of an enthusiastic crowd of 1,500 or so at Lens’ training facility, we started confidently, knocking the ball around well at the back.