Charlie MacDonald gave the O's the lead after nine minutes with his first goal for the club since arriving from MK Dons a month ago.
Then, having missed a penalty in the 15th minute, midfielder Martin Rowlands struck a stunning volley to double the host's advantage midway through the second half.
Substitute Michael O'Halloran goal had been on the pitch for just five minutes when he blasted home from close-range with 15 minutes remaining but it proved too little, too late for Rovers.
"I thought that it was a pulsating game, after all, they are the league leaders and we stayed on the front foot for virtually for the entire game," said Slade.
"We should have put the game to bed in the first period when I thought we played some of the best football we've done all season. Off the back of the defeat in the Johnstone's Paint Trophy on Tuesday, the lads deserve all the credit for that.
"I was delighted for Charlie MacDonald that he scored his first goal for us and he's got the monkey off his back. He'd had a couple of chances in previous games and he was disappointed not to have scored with those but this goal will do him the world of good.
"Martin Rowlands then scored our second with a wonderful finish and that's won us a football match. Yes, he missed a penalty earlier but it doesn't matter because he made up for it.
"Our whole team-talk was about staying on the front foot and trying to take the game to them by creating chances and going forward and not to sit back at any stage.
"Tranmere are top for a reason, they are resilient and they keep going right to the end and we saw that. They got a goal back and they were throwing bodies forward, there were six or seven bodies in our box trying to get the equaliser. That left them a bit open to the counter attack and perhaps we should have made better value of that. But it was a terrific win for us and I'm delighted."