The Riders couldn't score a touchdown and were held to a single point in the second half.
Quarterback Darian Durant was sacked eight times as the Bombers fed off 33,500 screaming fans in what is known as the Banjo Bowl, a follow-up to the Labour Day weekend game the teams play.
Saskatchewan won that one 48-25 last Sunday.
"I took my headset off a few times just so I could just relish the crowd noise," said a smiling head coach Tim Burke.
After the game, the Bombers announced they had traded veteran quarterback Buck Pierce to B.C. for non-import receiver Akeem Foster.
They said Pierce, who has been on the injured list for much of this season, wouldn't be available until Monday to discuss the move back to the team he left to join Winnipeg in 2010.
"Buck has been a true warrior and a consummate professional during his time Winnipeg and we sincerely thank him for his four years of service to our organization," said acting general manager Kyle Walters in the release.
They might not have wanted the news to overshadow what was for the struggling team (2-8) a major accomplishment as it tries to rescue this season.
"When you're playing against the No. 1 team in the league and defensively we come out and play like that, it just speaks (volumes) about what we can do as a defence," said cornerback Jovon Johnson.
"I said this on week two, this could be one of the best defences in the league if we just stick together and play and we showed that tonight man," said Demond Washington, who recovered a fumble and had one of Winnipeg's sacks.
Will Ford and quarterback Justin Goltz scored touchdowns for the Bombers, while Sandro DeAngelis added a field goal and picked up a single on a miss.
It was a complete reversal of last week's 48-25 loss in Regina with the Riders (8-2) only points coming from four Chris Milo field goals and a single.
Goltz and the offence struggled in the first half but found more life in the second and Burke gave new offensive co-ordinator Marcel Bellefeuille credit for some halftime adjustments.
For Goltz, making his second straight start after last week's 48-25 loss in Regina, it was also sweet.
"We needed this so bad, our city needed it and our fans needed it," said the quarterback, who Burke said will likely start the next game as well.
For Durant, it was a crushing loss after what has up until now been a tremendous season.
"You've got to give those guys a lot of credit they played at a level that we just didn't match today," said the veteran.
"In front of their home crowd, a game they really, really wanted, and they went out and got it."
As for how the Winnipeg blitz seemed able to shred the Riders offensive line, he said they will dissect what went wrong by looking at recordings of the game.
"I've got to give a lot of credit to (defensive co-ordinator) Casey (Creehan)," said Burke. "He came up with a really good blitz plan against these guys."
Burke also praised his secondary, which has received a lot of criticism lately.
He said he knew the defence was tired because of the time they spent on the field in the first half. The Bombers had the ball for only about three minutes in the first quarter.
"In the fourth quarter we just asked them to gut it out," Burke said.
The Winnipeg offence struggled at first but the stingy defence and special teams kept the Bombers alive, despite a slew of penalties.
Goltz threw his first pick at 1:35 and managed only two complete passes out of seven tries and 12 yards in the entire first half. He finished the game with eight completions out of 17 tries and 129 yards.
Durant completed 15 of 35 but managed only the same 129 yards.
The loss leaves the Riders tied with the Calgary Stampeders for the lead in the West Division and the CFL.
Milo scored first for Saskatchewan.
The only touchdown of the first half came on a 98-yard kickoff return by Ford, making his debut as a starter at tailback for an injured Chad Simpson, just over six minutes into the first quarter.
Milo's next two field goals gave the Riders a 9-7 lead until Bombers defensive back Marty Markett recovered a fumbled punt return.
Goltz connected with a diving Clarence Denmark in the end zone but the ball hit the ground first and it was ruled incomplete.
Winnipeg had to settle for a field goal and a brief 10-9 lead but Milo's fourth put the Riders back on top 12-10 as the half ended.
In the third quarter, Saskatchewan took a couple of costly penalties that killed an interception and set up Winnipeg's second touchdown of the game on a three-yard run by Goltz to make it 17-12.
Saskatchewan picked up a single on a punt but then a Durant fumble at the end of the third quarter set up Goltz's second touchdown of the game at the opening of the fourth to make it 24-13.
It capped a six-play 62-yard drive that was Winnipeg's most solid of the game to that point. DeAngelis missed at 40 yards and settled for a single to finish the scoring.
Goltz threw only one interception and Durant added another to make his season total two.Suggest a correction