The seventh-place finish saw Connacht entered into a play-off involving Bordeaux Bègles and Gloucester for a place in the next season's Champions Cup. Connacht played Gloucester away for the chance to face Bordeaux, and were leading 18–25 in the final minutes of the game when a penalty gave Gloucester a try-scoring opportunity and sent the match to extra time, after which Gloucester emerged 40–32 victors. Having lost the previous season's play-off, Connacht were entered into 2015–16 Challenge Cup where they topped their pool, before being knocked out by Grenoble in the quarter-finals. In the 2015–16 Pro12 however, Connacht broke a number of records on their way to a second-place finish in the regular season. This put the team through to the end-of-year play-offs for the first time where they faced Glasgow Warriors in a semi-final in Galway, winning 16–11. On 28 May 2016, a 20–10 win against Leinster in the Pro12 final gave Connacht their first ever major trophy. Connacht's Pro12 victory saw them qualify for the 2016–17 Champions Cup. They finished in third place in their pool, level on points with Toulouse in second to narrowly miss out on qualifying for the knockout stage of the competition for the first time. A serious injury crisis, which saw 21 players unavailable at the same time, contributed to the team sliding down the league table and they finished eighth in the 2016–17 Pro12. This saw the team entered into a play-off to qualify for the 2017–18 Champions Cup. A six-point loss to Northampton Saints saw Connacht entered into the 2Challenge Cup. This was Lam's last game in charge. It had been announced in December 2016 that he would leave at the end of the season to take over English side Bristol. The assistant coach of Super Rugby side the , Kieran Keane, was named as Pat Lam's replacement in February 2017, to take over ahead the start of the 2017–18 season. However, Keane's commitments with the Chiefs in Super Rugby kept him from linking up with Connacht fully until the end of that July. The league underwent further restructuring, with the addition of two South African teams and the division of the competition into two conferences. After a disappointing first season, in which Connacht finished second from bottom in their conference, Keane was let go one year into a three-year deal. The end of the 2017–18 season also saw the departure of long-serving player and captain John Muldoon who had made 327 appearances in his record-breaking career with the province.