Sligo Rovers will feel they still have a fighting chance of progressing to the Champions League third round despite falling to a 1-0 defeat to Norwegian champions Molde at the Showgrounds.
Daniel Chima Chukwu capitalised on a defensive blunder by Evan McMillan to score the only goal of the game three minutes before the interval.
The Bit o'Red face Molde at the Aker Stadion in the second leg on Tuesday evening.
The League of Ireland champions lined up without Danny North (knee), Aaron Greene (foot), Raffaele Cretaro (hamstring) and Danny Ventre (leg), while Haiti winger Pascal Millien missed out due to international commitments.
Manager Ian Baraclough brought Ross Gaynor and Jeff Henderson into his side in place of David Cawley and Alan Keane, who were both part of the Rovers team that drew 1-1 with Saint Patrick's Athletic at the weekend.
Molde boss Ole Gunnar Solskjaer made two changes to the side that drew 1-1 with Viking at the weekend, with both Vegard Forren and Chima coming in for Evan Hofland and Etzaz Hussain.
Sligo were searching for only their second ever victory in European competition and almost gifted Molde an early lead with six minutes played.
Adiou Coly nearly made the most of Joseph Ndo's misplaced back pass but Gavin Peers did just enough to block down Coly's shot at goal.
Most of the early exchanges were played out in front of the Sligo danger area in the searing Showgrounds heat.
However, Sligo were unlucky not to take an unexpected lead on 23 minutes when roaming centre half Henderson set up David McMillan. The former UCD poacher ran at his marker before opening up space for himself inside the area, but he saw his low drive palmed away by Molde netminder Orjan Nyland.
Chima lobbed the ball over Gary Rogers' crossbar after he overcame the challenge of three Sligo defenders on 27 minutes, before Rogers did well to block Senegalese striker Coly's daisy cutter at his near post two minutes later.
Rovers had their goalkeeper to thank again on 37 minutes as he got both fists behind Chima’s rasping volley.
Seconds later the Nigerian teed up Jo Inge Berget, but the Norwegian midfielder fluffed his lines as he sent the ball wide of Rogers' post, despite having plenty of time and space.
The Molde pressure eventually took its toll on 42 minutes as Evan McMillan failed to clear a long punt. Chima latched on to the ball and showed good strength in holding off Peers before sending a curling shot past Rogers and into the Sligo net.
The Tippeligaen champions almost doubled their lead a minute into stoppage time. Rogers' attempted clearance from a poor Lee Lynch back pass was chased down by Berget, with the Meath native looking quite relieved to see the ball roll narrowly wide of his post.
Berget then sent his 51st minute effort well over the Sligo crossbar having been set up by Martin Linnes,
Joona Toivio saw his shot from 10 yards deflected away for a corner off the legs of Anthony Elding on 63 minutes as Rovers struggled to link play between a five-man midfield and the afore mentioned striker.
Ndo dragged his 67th minute shot wide of Nyland's goal after he did well to rob Mattias Mostrom of possession at the edge of Molde's area.
Belgian official Alexandra Boucaut waved away Elding's claims for a penalty on 75 minutes, three minutes before Molde captain Daniel Berg Hestad headed wide from a Zlatko Tripic cross.
Substitute Kieran Djilali spurned a golden opportunity to level the tie ten minutes from the end.
Elding did well to keep Gaynor's searching cross in play before finding the former Crystal Palace man in space. However, Djilali failed to keep his acrobatic effort down as the ball soared high in to the stand.
The Bit o'Red introduced 19-year-old striker Liam Martin in place of Davoren late on but not even the exuberance of youth could bring the Airtricity League side back into the tie.
Sligo Rovers: Gary Rogers; Jeff Henderson (for Alan Keane 72), Evan McMillan, Gavin Peers, Iarfhlaith Davoren (Liam Martin 78); David McMillan (Kieran Djilali 59), Joseph Ndo, Seamus Conneely, Lee Lynch, Ross Gaynor; Anthony Elding.
Subs not used: Ciaran Kelly, David Cawley, Ryan Connolly, Jake Dykes.
Molde: Orjan Hyland; Martin Linnes, Joona Toivio, Vegard Forren, Magne Simonsen; Mattias Mostrom (for Zlatko Tripic 76), Emmanuel Ekro, Daniel Berg Hestad (Evan Hofland 84), Jo Inge Berget; Adiou Coly (for Agnaldo Moraes Jr 62), Daniel Chima Chukwu.
Subs not used: Olde Soderborg, Kristoffer Vatshaug, Etzaz Hussain, Magnar Odegard.
Referee: Alexandra Boucaut (Belgium)