Steve Bruce's side lost 2-0 at home to Derby County on Tuesday night but reached Wembley with a 3-2 aggregate win.
Derby, who were the only team to win a Championship match at Hull's KC Stadium during the regular season, took the lead after just seven minutes of the return match through Johnny Russell.
Nine minutes before half-time Andrew Robertson, who scored what proved to be the decisive goal deep into injury-time of the first leg, turned into his own net as Hull's commanding position crumbled.
However, despite sustained pressure from the visitors, it was Bruce's side who held on to reach a Wembley clash with Yorkshire rivals Sheffield Wednesday and keep alive their dream of returning to the Premier League after just a single season in the Championship.
The long-awaited final whistle sparked wild celebrations and a mass pitch invasion from the home fans, but for those watching on Twitter, at least, it was a hugely uncomfortable watch.
Here is just some of the reaction from Tigers fans as they began to piece together their shredded nerves.
The anxiety Hull caused me was ridiculous. Shocking performance, Derby so unlucky and was a credit. Hope we make up for it! WEMBLEY!— Gaz Williams (@GazzaWilliams10) May 17, 2016
Don't really feel like celebrating after that performance. Typical Bruce don't let them score 3! Difficult watching but we're there! #hcafc— Dan Warelow (@_dan_82) May 17, 2016
Just lost another 5 years of my life span. But hell it's worth it #hcafc— Dare to Dream (@craig_tigers) May 17, 2016