saw the introduction of a play-off system for the top four teams, Munster met and lost 16–6 to Leinster in the play-off semi-final. The 2010–11 season saw Munster drawn in pool 3 of the Heineken Cup alongside Ospreys, London Irish and Toulon. Munster lost 23–17 away to London Irish, before defeating Toulon 45–18 at Thomond Park. Munster defeated Ospreys 22–16, but lost the reverse fixture at Liberty Stadium 19–15. In round 5 Munster went to Toulon, losing 32–16. As a result, Munster failed to qualify for the quarter-finals of the Heineken Cup for the first time in 13 years. Munster won their final pool game, at home to London Irish, 28–14, and qualified for the 2010–11 European Challenge Cup quarter-finals. Munster defeated Leinster 24–23 on 2 April 2011 in the Celtic League, ending a run of 5 straight defeats against their provincial rivals. Munster beat Brive 42–37 in their Challenge Cup quarter-final to qualify for the semi-final against Harlequins on 30 April. Munster lost the semi-final in Thomond Park 20–12. Munster finished first in the 2010–11 Celtic League. They beat Ospreys 18–11 in their semi-final to set up a Grand Final with Leinster, which Munster won 19–9, securing a third Celtic League title. Munster were drawn in pool one for the 2011–12 Heineken Cup, alongside Northampton Saints, Scarlets and Castres. They beat Northampton 23–21 in the first pool game at Thomond Park, after an 83rd minute drop-goal from Ronan O'Gara. In their second pool game, Munster beat Castres 24–27, with O'Gara again scoring an overtime drop-goal to secure victory. Munster won their third pool game, away to Scarlets, 17–14. In the return fixture a week later, Munster won 19–13. A 26–10 win over Castres on 14 January 2012 ensured that Munster qualified for the quarter-finals of the 2011–12 Heineken Cup. Munster ended their 2011–12 Heineken Cup pool fixtures with a 51–36 victory against Northampton Saints, securing the top seed in the quarter-finals and winning 6 out of 6 pool matches for the first time. Munster lost their quarter-final against Ulster 22–16, losing just their second match at home in the Heineken Cup. Munster finished third in the 2011–12 Pro12, and played Ospreys away in the play-off semi-finals, losing 45–10. It was announced on 22 February 2012 that McGahan would be leaving Munster at the end of the 2011–12 season, to take up a role of coaching co-ordinator on Australia's management