Tony Mowbray congratulated Cardiff after his Middlesbrough side lost 2-1 at Watford which ended any slim hopes of a play-off place.
The Bluebirds' victory at Crystal Palace rendered the outcome of the game at Vicarage Road irrelevant in terms of the play-off picture, even if Boro had got the win they required.
Mowbray said: "I congratulate Cardiff on achieving the result they required.
"I think to lose here is a little bit harsh. When you're in a position where you've got to win you gamble from a position of being 1-1 to try and get the three points.
"We lost trying to win but it didn't really matter, Cardiff got the job done. Ultimately over the course of the season we fell just short."
Boro could have been comfortably in front by half-time were it not for some excellent saves from Scott Loach.
The former England Under-21 keeper returned after a 13-game absence from the starting XI in place of on-loan Tomasz Kuszczak after his partner gave birth earlier in the day and Mowbray said: "We were quite surprised to see Loach on the team sheet to be honest, Kuszczak's been playing but the kid comes in and makes some very good saves, some important saves.
"I think there's some stat that when we go in front we very rarely lose a football match and the opportunity was there first half to do just that.
"Credit to them (Watford). They're a very resilient team. You can see they're a team that work extremely hard for each other, they have a certain way of playing and they believe in it and they keep going at it."
The win ensured Watford finished the season on 64 points and 11th in the table - some achievement for a team that was written off widely before a ball had been kicked last August.
Hornets boss Sean Dyche said: "It's a fantastic way to end the season for all concerned, especially having been written off heavily before the season even started, then it's fair to say myself had been written off after about 12 games but we ended up with not just a positive finish, but a positive run of form from a group of players that's developed considerably over the season."
The Hornets took just 10 points from their first 13 games but asked if there was some frustration about what might have been possible had his team started the campaign better, Dyche responded: "I think to be honest it's amazing I'm being questioned about things like that.
"We've had our moments of luck, as we had first half today, and we've had our moments of bad luck.
"You can look at many but one for starters is 14 penalties not being given. Over a season you believe in balances, maybe it balanced today with Scott pulling off some good saves in the first-half."
After Loach had made at least three top quality saves to prevent Boro going in front before half-time, the Hornets took the lead when Chris Iwelumo flicked home Troy Deeney's near-post cross to score his first goal at Vicarage Road since moving to the club last summer.
Although Marvin Emnes equalised with six minutes to go, Boro paid the price for pushing men forward in search of the winner when Deeney started and finished a counter attack late on.
