My third longest but highest average power over that distance, a tad under 60km. It was a group ride with close to 200 riders at between 2.5 and 3.2W/kg but seemed to be more at the 3.2 end of the spectrum than the 2.5. Consequently I found it hard going.
I twice got dropped but managed to claw my way back. I didn't manage it a third time, getting dropped and staying dropped with about 15 minutes to go. I rode in with another rider in a mini peloton of two. I knew I'd worked out by the finish.