The Cherry and Whites beat west country neighbours Bristol 35-13 at Ashton Gate and will play Saracens at Kingsholm on Saturday in the semi-final of the Premiership play-offs.
Bristol, playing their second Premiership game in five days, finished third and will travel to Welford Road to face runners-up Leicester.
Ryan said: "Play-offs are knockout rugby and they require a slightly different approach - as a coach the nine months is about environment and week to week.
"I'm delighted and I always knew that this group were capable of it."
On today's performance he said: "We dithered a bit but we matured so I'm pleased they got their just rewards.
"We know Bristol have been successful when people think they can run them around - but you can make a lot of mistakes when you do that.
"We knew we had to set a platform and we missed a couple of opportunities - but I think it was relatively successful.
"We got a few cheap tries through mistakes, but also gave away a couple of silly ones as well so we could have made that scoreline more flattering towards ourselves."
England head coach Brian Ashton may have more worries of announcing his 32-strong squad for the summer tour to South Africa on Tuesday.
Gloucester number eight James Forrester was stretchered off after just five minutes and Ryan said he had suffered ligament damage in his knee and could be facing a long term lay-off.
There is no silverware for being top of the table after the 22-game season but Ryan accepts the tournament now includes the play-offs.
He added: "We recognise we have to play two games in a slightly different environment but it is now Cup rugby.
"You have to win to stay in and if you do win you have to go to another game to get called Premiership champions.
"We have always known that but it doesn't remove what we have achieved to date after nine months with a very young group - to be top of the pile is a significant achievement.
"We now face a tough game against Saracens who will be hurting after losing two big games.
"We have to win that one to get to the Twickenham final.
"We didn't feel out of place here at Ashton Gate because we know we have the backing.
"We know that we can fill Kingsholm, even though it will be slightly different because of the building work."
Bristol, who beat Leicester at this venue on Tuesday night - and head coach Richard Hill accepts today was always going to be testing, especially for his ageing pack.
Hill explained: "We could have made a lot of changes but this was too big a game to do that.
"It was a pretty brave effort from the players, particularly the forwards, to produce another big performance in the heat.
"We didn't help ourselves, Gloucester played a very simple game - played territory, kicked to the back three.
"That was exactly what our tactics were supposed to be - but we didn't quite get there.
"There was a little lack of composure perhaps on the day, maybe lack of concentration during a bit of tiredness.
"But we certainly made too many errors to get any sort of worthwhile possession.
"We're disappointed we lost this game but to finish in the top four and into the play-offs is a first for the club. It is a superb achievement from everyone concerned."