Manager Mark McGhee is frustrated to have missed out on fourth place but is content with Motherwell's season.
Motherwell were 3-1 winners at Ross County but cannot catch St Johnstone after the Perth side beat Celtic.
"We kind of hoped we might make fourth and we haven't so there's a little bit disappointment," said McGhee.
"But we'll reflect in the end and we'll be satisfied that fifth is a decent show. Of course, we're overjoyed to make the top six."
A dominant early display provided the platform for victory with Stephen Pearson and Keith Lasley putting Motherwell two up after just 16 minutes.
The visitors threatened to run away with it in the first half but Ross County battled back with Liam Boyce reducing the deficit before Pearson nodded home his second deep into injury time.
"It was a sunny night and we started with sunny football," enthused McGhee. "We played some good stuff, created chances, scored two goals and looked comfortable.
"Any opportunity for us to run away with it was gone because they made changes but overall I think we did enough to win the game and deserved it."
The club are in negotiations with a number of senior players who are nearing the end of their contracts and now know how much finance will be available.
"We know the importance of these players," McGhee explained. "Stephen McManus, Stevie Hammell, Keith Lasley and Scott MacDonald have been terrific all season but we have to cut our cloth accordingly. Hopefully we will get it sorted."
Ross County will have to settle for sixth place and manager Jim McIntyre is disappointed with the post-split form.
"We wanted to make sure in the five games we tried to move up at least a place," he said.
"Overall, in the context of the season we wanted to try and get top six, we managed that and we wanted a decent cup run and we managed to win the cup.
"As disappointed as I am tonight, I'm sure we'll reflect in a few weeks time and be satisfied with our season's work."
McIntyre bemoaned a sluggish start from his side but was happy with the response in the second half.
"We were very sloppy, slow out the traps, made some very basic errors and that afforded Motherwell a good bit of pressure and they've scored and deservedly so," he said.
"We created a host of chances but couldn't quite put the ball in the net. You're always going to be susceptible to the counter attack and we've been punished right at the death.
"Motherwell showed better quality on the night when it came to putting the ball in the net.
Liam Boyce netted just this second goal of 2016 with McIntyre hoping the striker can rediscover his early season form after a summer break.
"It's been a frustrating time since Liam broke his hand," he explained.
"It was great seeing him getting back on the scoresheet. I thought he did well and it was nice to see him hopefully get a goal that will help him get to the Euros with Northern Ireland."