Across the two legs, clear-cut chances were few and far between, and it took a brilliant Gustavo Hamer effort to make the difference across 180 minutes and added-on time.
Despite failing to have a single shot on target in either game until Hamer's decisive goal, Mark Robins's Coventry were deserved winners over a Boro side who had lost their way during the run-in.
When there were minimal strikes on target during the goalless first leg, the game itself was a relatively drab affair, but it was a different story during the opening 45 minutes in the North-East.
Despite neither goalkeeper being tested until added-on time, both teams showed ambition in the final third with either a poor final pass or efficient defending keeping the score goalless.
The best chance of the half went to Boro defender Darragh Lenihan, whose made solid connection with his header but was denied by goalkeeper Ben Wilson.
After the break, it was more of the same, the nerves being felt by both teams and their respective supporters, but the breakthrough came before the hour mark as Coventry went ahead with their first shot on target in the tie.
Viktor Gyokeres initially breached the offside trap and beat Zack Steffen to the ball, but after Hamer took over and kept his composure, the midfielder magnificently found the roof of the net from 15 yards out.
The expected response from Boro did not come, and Hamer almost doubled Coventry's advantage from a free kick, whipping an unstoppable effort towards the crossbar only for it to strike the crossbar.
Boro finally pushed hard during the latter stages, having a goal disallowed for a clear offside and sending countless balls into the penalty area, but Coventry stood firm to ensure that either the Sky Blues or Luton will be playing Premier League football in 2023-24.