Dominic Hyam's early strike helped Coventry to a crucial 2-0 victory over Barnsley as they moved nine points clear of the Championship relegation zone.
Substitute Matty Godden sealed the three points in stoppage time as the Sky Blues secured a deserved win over their play-off chasing opponents.
Buoyed by news that third-from-bottom Rotherham had been beaten by Coventry's landlords Birmingham earlier on Sunday, Mark Robins' men produced a gutsy performance to edge past their Yorkshire opponents in a game of few chances.
For Barnsley, defeat saw their impressive away form brought to a shuddering halt.
The Tykes had won six on the spin on their travels but they struggled to get going against a well-organised Coventry side, who defended strongly, and - barring one late chance - stifled the danger of in-form Daryl Dike.
The Sky Blues were well worth their first-half lead and although the visitors stepped up their intensity after the break, they rarely looked like making a breakthrough in a disappointing overall performance.
After a quiet opening, the Sky Blues, on the back of a crucial win at Rotherham last time out, took the lead after nine minutes.
A quick throw-in caught Barnsley off guard and Max Biamou chested the ball into the path of Hyam, who lashed it home with a sweet right-footed finish.
The early goal lifted the Sky Blues and Leo Ostigard sent a looping header over as they took control of the proceedings.
The Tykes had to wait until the 24th minute for a half chance, Romal Palmer's header failing to trouble home goalkeeper Ben Wilson.
That aside, Alex Mowatt's set-pieces looked the most likely way for the visitors to get back into the game although there were good chances for both sides as half-time approached.
First, Scottish defender Hyam went close to adding his second, heading over a Sam McCallum long throw.
And then, on the stroke of half-time, Tykes top scorer Cauley Woodrow hooked the ball wide after latching onto a through ball inside the box.
The visitors came out with more purpose after the break and Mads Andersen headed wide from a Mowatt free-kick.
But the Sky Blues had a sniff of an opening themselves after 65 minutes as substitute Viktor Gyokeres saw a fierce drive blocked by Michal Helik and McCallum struck an effort wide from the resulting corner.
The Tykes, looking to extend their four-point advantage over seventh-placed Reading, went close after 71 minutes but Wilson did well to block substitute Dominik Frieser's close-range effort.
Dike also had a late chance to rescue a point for the visitors but fired into the side-netting and Godden made them pay as he smashed home in stoppage time to put the result beyond doubt.
Godden could even have netted a second as the home side countered on the break but was denied by Brad Collins.
What the managers said...
Coventry's Mark Robins: "The quality in the game is bereft a little bit now because the stakes are so high. But within it we played some good stuff and we did what we needed to do to. To break Barnsley down is really difficult because of the way they come after you but we managed to get the result.
It was a much-needed win. There are still games to come and points to play for so I wouldn't want anybody thinking it was job done. We need to get into the 50s. That has to be the aim. We need to put as much distance as we can between us and the teams around us but there are also teams we can catch in front of us and that has to be the challenge for us."
Barnsley's Valerien Ismael: "It was not enough today. The first half, we didn't shoot on target. The second half was better but over the 90 minutes, Coventry deserved to win. They were well organised and we were not good enough. But it's not time to complain. We just have to focus on the next game.
"We have put in a big effort so far and we move quickly on to the next game now. We need to bounce back. We are still in a strong position. We have had 42 games so far and we have performed incredibly. We are proud of the guys so we have just told them, 'forget that game now, move on in your head'. We have four games left and we have to be ready."