Conor O'Shea hailed Harlequins' mental strength after beating Bath to secure the last Aviva Premiership play-off spot.
Quins' hopes of finishing in the top four seemed all but over a month ago but a nail-biting 19-16 win over Bath saw O'Shea's side leapfrog their opponents into fourth on the final day of the regular season.
Despite George Ford's brilliant solo score in the first half, Mike Brown's try and four Nick Evans penalties were enough to seal a fifth consecutive victory for Quins, who next take on title favourites Saracens in their semi-final.
O'Shea said: "There was a huge amount of tension and I'm incredibly proud of the belief within that group.
"We've won 13 out of our last 17, we've won our last five in a row, we've had to scrape wins but mental strength is a huge thing.
"It doesn't happen by accident, you don't just turn one-point wins and two-point wins your way, it comes from a huge belief in each other.
"We'll give it a good crack against Saracens, we'll play our way and if it isn't good enough I won't change the way I feel about what this group has done and what it will go on to do."
Sarries won 39-17 when the two teams met at Wembley in March but O'Shea insists Quins know how to hurt the Men in Black.
"We'll be completely written off, I'm pretty comfortable with that - you can write this team off any day," O'Shea said.
"Looking back at the Wembley game, we weren't far off and we had a few key players who weren't playing that day who are back in.
"If you look at the game in general there wasn't a huge amount between the sides.
"You might laugh at that but I came away from that game confident we can do something if we play them again.
"The blueprint is there, we know what to do - we have to go and execute it and take our opportunities."
Bath head coach Mike Ford admits dropping out of the top four on the last day of the season is a bitter pill to swallow.
"I've never been as disappointed in my life since being involved in the game," Ford said.
"I don't want any sympathy, we should have got to the top four today and we didn't.
"Is it because the team is young? No, the team is good enough to do it, we should have done it.
"Maybe in July I might come round a little bit and think it's been a good season.
"The main thing for us is we're only a year into this group and the potential is enormous, absolutely enormous."