Gillingham broke Crawley hearts late on as he won the game for his side with just a couple of minutes remaining.
Lee was waiting after Reds failed to deal with a corner which saw Crawley suffer their first defeat in their last ten games.
There were three changes for the Reds starting XI as Hiram Boateng, Mark Connolly and Josh Simpson were replaced; Jamie Proctor, Dannie Bulman, and, Joe Walsh - who played for Wales under-21s in midweek, came back into John Gregory’s team.
Reds began brightly and after only three minutes, Proctor’s teasing header just eluded the on-rushing Matt Tubbs at the back post.
Gillingham’s opening opportunity came just a few minutes later when a Jake Hessenthaler corner was met by Craig Fagan. The ball skipped across Paul Jones’ six-yard box and Gregory’s men were lucky that Leon Legge smashed over.
After 15 minutes, Reds had a superb opportunity to go as Mike Jones’ cross found Billy Clarke Unfortunately for Crawley’s Irish star, his effort was inches wide of Stuart Nelson’s right-hand post.
Just before the half hour mark, a good counter attack saw Proctor run from his own half before finding Clarke on the left. However, the Reds no. 7 blazed over the bar.
Minutes later and Gillingham had a great chance. Another Hessenthaler corner was awkward for Paul Jones and Gills loanee Joe Pigott saw his effort fly over the bar.
With ten minutes of the first half remaining Reds had two great chances. Clarke had an effort that tested Nelson, and then, after Proctor’s deflected effort trickled across the six-yard box and Tubbs was inches away from netting.
The visitors had another opportunity when a corner found the head of Kyle McFadzean whose accuracy was off and the ball sailed over Nelson’s goal.
Crawley came out after the break and straight away got to work on getting a goal with Tubbs hitting an effort over the upright after a Mike Jones pass.
A minute later and Tubbs tested Nelson with an effort although it was comfortable for the goalkeeper.
Gills had some pressure of their own and the tall Leon Legge headed over the bar from another corner.
On the hour, Clarke had another opportunity when Sadler found him with an aerial ball but Adam Barrett made a sensational block to deny the Reds man.
From the corner Tubbs’ effort was hacked clear on the line by Hessenthaler.
Crawley ‘keeper Jones pulled off a great save to deny Cody McDonald and then Myles Weston smashed an effort wide of the target.
On 67 minutes McDonald had another chance as his volley was palmed over by Jones as the game went from end-to-end.
At the other end, Proctor hit an effort over after a neat drag back by Mike Jones before an acrobatic effort from Tubbs was cleared.
Gregory changed things up with 20 minutes of the game left as Rory Fallon made his Crawley debut at the expense of Proctor.
McDonald’s snapshot with 11 minutes remaining was dealt with comfortably by Paul Jones after an Adebayo Akinfenwa flick on.
Crawley could have won the game on 84 minutes when Walsh hit the post with a header and then Clarke headed millimetres wide from a Drury ball in.
With three minutes remaining the home side did take the lead when a corner wasn’t dealt with and substitute Charlie Lee mis-kicked his effort and it somehow finally found a way past the man on the post and into the back of the net.
Reds couldn’t find a late equaliser and the away support made an unhappy trip home from Kent.
REDS: P. Jones; M. Connolly, McFadzean, Walsh, Sadler; M. Jones, Drury (c), Bulman, Clarke, Tubbs, Proctor (Fallon, 72)
UNUSED: M. Connolly, Torres, Maddison, Kaikai, Boateng, Dicker