Morecambe moved up to third in the Conference table with this battling victory in atrocious conditions at Christie Park.
It was Morecambe's eighth home victory of the season and came after the best possible start when they took the lead after just 14 seconds.
Garry Thompson was again the Shrimps goal hero with his third in four games when he latched on to an excellent throughball from Lee Elam to score coolly past the stranded Paul Wilkerson.
Morecambe, enjoying an excellent start to the game almost made it 2-0 on 13 minutes, but Danny Carlton was denied by an excellent goal-line clearance from Gravesend defender Aaron Barnett.
Only then did Gravesend begin to find some fluency and Gary Abbott forced Craig Mawson into his first save of the day with a neat strike.
The visitors then saw Danny Lye and Che Stadhart both come close before the busy Abbott was unlucky to fire an overhead kick inches over the bar.
Gravesend's resistance failed to reach a rousing crescendo, however, as Morecambe took control again in the second period.
On 53 minutes, Wilkerson had to be at his best to tip over a Jim Bentley header just minutes before Gravesend were reduced to ten men when the influential Barnett was given a straight red card for a challenge on Carlton.
The Shrimps then made their numerical advantage count and Adriano Rigoglioso coming close on two separate occasions with Wilkerson saving well from a low shot and Justin Skinner clearing a curling corner off the line on 62 minutes.
Morecambe finally added a second on 69 minutes when after some good work down the right from Carlton, Michael Stringfellow touched the ball on for the unmarked Elam who sidefooted the ball past the stranded Wilkerson.
There was still time for more controversy when the promising Carlton became the second player to be shown a straight red card after he upended Skinner with a rash tackle from behind