The hosts dominated possession for large periods once Hatters were down to 10 men with Jordan Cook dismissed on the half hour, but Town stood firm, restricting their opponents to very little in terms of clear-cut chances.
Under-fire Slade, who has seen the Mariners now go nine games without a win, said: "It was a strong performance without the result really.
“I didn’t think we had too much luck going our way. They were a bit fortunate with the goal they scored.
“I thought we did enough to win the game, and that’s top of the league so it’s frustrating at the minute, but we’ve just got to stay really, really positive because I think there were some good performances out there.
“They had 10 men for some of the game, but it didn’t matter. The first half-hour we were the best side, we’ve hit the crossbar.
“I thought we were forcing the issue all the way throughout the game. I think the only shot they’ve had is from the free-kick.”