Hendon still looked dangerous on the break, however Conway made it three before half time and orient smelt blood going into the second half.
Hendon pulled a goal back through Craig Phillips to make it 3-1, however this seemed to spur Orient on for more.
Lester, who was causing havoc from the first minute, got in on the act with two goals to make it 5-1.
Orient weren't finished, the goal of the day was saved until the end. Sinclair picked up the ball from 20 yards and found the top corner with a brilliant shot for 6-1.
Loughton Orient manager Dan Curtis told JC Sport: "I'm very pleased with the performance today. We played nice football at times and were clinical in front of goal. More of the same next week to finish the season will be nice."
Hendon player-manager Craig Miller told JC Sport: "We didn't bother turning up for a dead-rubber, but I believe we've got the hallmark for a push for promotion or even the title next season."