He was noticed in his own country, then moved to Bristol Shoguns ahead of the 1998–1999 Allied Dunbar Premiership Two season, where he became the first ever Uruguayan professional rugby player.

[2] He moved to Stade Français for the 2000–01 French Rugby Union Championship, where his side progressed to the quarter-finals in his debut season.

Haven finished seventh in consecutive seasons with Montauban, Pablo moved to Avenir Valencien in the Fédérale 1, before returning home to Uruguay in 2010, playing with Montevideo Cricket Club, before retiring in 2012.

His last game was on 27 November 2010 against Romania in the 2011 RWC final place play-off match, where they failed to qualify for the 2011 Rugby World Cup.

Though this was a short stint, as he was later named head coach of the Uruguayan national side on a 4-year contract, with the aim of qualifying for the 2015 Rugby World Cup.

The opening leg of the play-offs saw Uruguay draw 27–27 in Montevideo, but lost 32–13 in the return fixture in Kennesaw, Georgia, which sent Lemoine's men to the repechage qualification.

On 2 August 2014, Uruguay beat Hong Kong 28–3, to set up a home and away series against Russia to claim the final sport in Pool A.

Uruguay failed to claim a win during the 2015 Rugby World Cup, losing all their matches in their group; 54–9 to Wales, 65–3 to Australia, 47–15 to Fiji and 60–3 to England.

[7][8] Lemoine left his role with the URU in early 2018 following his appointment as the German national team head coach.

Lemoine led Germany into the 2018 Rugby Europe Championship, needing at least three victories to put them within a chance of World Cup qualification.