Wrexham hoped for a win to help lift spirits at the end of a troubled week but there was no sympathy on the pitch from a determined City side.
Supporters of other clubs from across the country went to the Racecourse Ground to show their solidarity with the threatened Welsh club and helped boost the gate to more than double the usual attendance for a league game.
Nearly all were wearing an item of red to show their support and fans had the unusual sight of a Sunderland supporter standing in front of the home crowd conducting the Welsh choir.
Wrexham held their own early on as Mark Jones tested goalkeeper Steve Phillips with a fierce shot and then Stephen Roberts hit the crossbar. Another shot from Jones was blocked and Darren Ferguson's curling free-kick was held under the bar.
Luke Wilkshire saw a shot deflected giving home keeper Matt Baker a tricky save before Dennis Lawrence gave away a penalty. Stephen Brooker crossed to the far edge of the box where Leroy Lita was upended by Lawrence's tackle, and Mickey Bell stepped up to send Baker the wrong way.
Scott Murray put the Robins further in front before the break, hitting an angled shot from Tony Dinning's cross.
When Brooker added the third early in the second half there was no way back for the home side, but the goal had a touch of luck about it. Bell's long, low shot was going wide until Brooker got a foot to it a few yards out to leave the luckless keeper stranded at the other post.
Lita saw a shot beaten out when he seemed certain to add a fourth goal, then Craig Morgan put in a crucial tackle to deny Brooker.
Chris Armstrong's goal, an easy tap-in, was no less than he deserved for nipping through the City defence, but it came too late to change the game. He headed against the crossbar in the last minute, hoping to give the big crowd something to cheer.