Match ends, Northern Ireland 1, Bosnia and Herzegovina 2.
Northern Ireland made a disappointing start to their inaugural Nations League campaign as they lost 2-1 to Bosnia-Herzegovina at Windsor Park.
The hosts dominated but fell behind to Haris Duljevic's 36th-minute close-range flick from Edin Dzeko's cross.
Elvis Saric slotted into the empty net after a mix-up between defender Craig Cathcart and goalkeeper Bailey Peacock-Farrell on 64 minutes.
Substitute Will Grigg hooked in a consolation goal in injury-time.
- Relive the key moments from Saturday's Nations League action
- O'Neill praise for dominant but defeated Northern Ireland
Northern Ireland were on top for the vast majority of the game, orchestrating wave after wave of attacks, but passed up a series of goalscoring opportunities and it was the visitors who proved more clinical.
The defeat deals a major blow to NI's hopes of success in the new competition which aims to eliminate the number of friendlies played in favour of more competitive games.
Bosnia-Herzegovina host Austria in their next fixture in Group B3, while NI manager Michael O'Neill is expected to take advantage of the opportunity for some experimentation when his side face Israel in a friendly in Belfast on Tuesday.
The men in green then face a difficult double-header away to Austria and Bosnia-Herzegovina in mid-October, before a friendly with the Republic of Ireland and then their final Nations League match at home to Austria in November.
O'Neill adds youth to experienced line-up
O'Neill handed Leeds United keeper Peacock-Farrell the number one jersey after the 21-year-old's impressive start to the season, which has seen him keep three clean sheets in six games for the Championship leaders.
The former Under-21 international was chosen to start ahead of Norwich's Michael McGovern, who played every minute of the previous World Cup qualifying campaign and Trevor Carson of Motherwell, who had been picked for the three most recent friendlies.
Peacock-Farrell distinguished himself by parrying Roma striker Dzeko's well-struck first-half shot but a misunderstanding with Cathcart, when he failed to collect the Watford defender's backward header, allowed Saric the simple task of slotting home for his first international goal.
The NI manager also gave a second international start to left-back Jamal Lewis as he aims to make that position his own following the retirement of Chris Brunt.
Captain Steven Davis, one of a number of players lacking regular first-team football, set-piece specialist Oliver Norwood and new Middlesbrough signing George Saville were restored to midfield after missing the summer tour to Central America and stamped their authority on proceedings for long periods.
Missed chances costly for hosts
Northern Ireland were left to rue a plethora of missed chances but were denied a penalty in the first minute when Saville appeared to be brought down in the area by Erin Zukanovic with referee Pavel Kralovec waving play on.
The home team enjoyed 64% of the possession in the first half, pressing high, producing some enterprising play and forcing six corners to their opponents' none.
Niall McGinn and Stuart Dallas proved a major threat on the flanks, but a tally of 10 attempts on goal but only two on target told its own story for the hosts who, despite their superiority, failed to carve out many clear-cut chances.
McGinn's effort was well saved by Ibrahim Sehic, Dallas fired wide and Saville squandered another opportunity for an opener as their side failed to translate their relentless pressure into tangible reward.
A lack of composure in front of goal was evident again after the interval as Dallas volleyed into the ground from McGinn's inviting cross, which allowed Sehic to push the ball over the bar, and then Kyle Lafferty's back-post header after a Jonny Evans flick-on was brilliantly denied by a stunning save from Sahic.
Boyce forced Sahic into another fine stop, before Grigg celebrated his return to the international fold after a two-year absence by hooking in a close-range finish from fellow substitute Liam Boyce's assist for his second Northern Ireland goal.
The Wigan forward had a late chance to level but could not make the necessary contact.
Boost for manager Prosinecki
Bosnia-Herzegovina were playing their first competitive game under new manager Robert Prosinecki, having conceded just two goals in six games since the former Croatian midfielder took charge in January.
Prosinecki, who lost 4-0 on his last visit to Belfast as Azerbaijan manager in November 2016, was appointed after the Bosnians had followed up their failure to qualify for Euro 2016 by not making the 2018 World Cup finals in Russia.
Former Manchester City striker Dzeko equalled Emir Spahic as his country's most capped player with 94 appearances and played a key role by providing the low left-wing cross which set up Duljevic for his first international goal.
Conor McLaughlin could have done better in preventing the cross while Duljevic should have added a second in the second half but his effort just grazed the post.
Northern Ireland face uphill struggle
The Nations League sees similarly ranked countries face each other on a home and away basis with promotion and relegation between leagues at stake, plus seedings for the European Championship qualifying draw in December and a potential backdoor route to the Euro 2020 finals.
A second successive appearance at a European finals is the ultimate aim for the Northern Irish and this game was their fourth of 2018 as they build up to the start of that qualifying series, which runs from March to November 2019.
A 2-1 home win over South Korea was followed by a 0-0 draw with Panama and a 3-0 loss to Costa Rica, but this was their first competitive outing since that heartbreaking two-legged reverse to Switzerland in a World Cup play-off 10 months ago.
This was the first meeting between Northern Ireland and Bosnia-Herzegovina, who are ranked 12 places below O'Neill's men in the Fifa standings.
Defeat leaves the home side, who have now won just one of their past eight fixtures, with an uphill struggle to make an impact in the competition.
- Since a run of five consecutive victories between March and September 2017, Northern Ireland have won just one of their past eight games (D2 L5).
- Bosnia-Herzegovina have won back-to-back games for the first time since March 2017, having won 3-1 against South Korea in their previous outing.
- Northern Ireland have lost three of their past four home games (W1), as many as they had in their previous 21 on home soil (W12 D6).
- Northern Ireland have conceded in four consecutive home fixtures for the first time since March 2013 (a run of seven games).
- Northern Ireland had 26 shots (inc. blocks) compared to just five for Bosnia and Herzegovina. The away side scored with two of their three shots on target.
What they said
Northern Ireland manager Michael O'Neill: "I am disappointed to lose the game, but there were a lot of positives to take from our performance.
"We gave away two poor goals which is out of character for us, but once again we showed a lot of spirit and created a lot of chances.
"We played some fantastic football, our movement was excellent and for the first 30 minutes the game was played almost entirely in their half."
Northern Ireland captain Steven Davis: "There were a lot of positives to take from the game. We have definitely played a lot worse and won.
"We made a fast start and there was a good energy to the team. We need to be a lot more clinical in the future."
- 2McLaughlinSubstituted forBoyceat 70'minutes
- 7McGinnSubstituted forWardat 76'minutes
- 10LaffertySubstituted forGriggat 69'minutes
- 12SehicBooked at 83mins
- 2CivicBooked at 10minsSubstituted forZakaricat 76'minutes
- 21SaricSubstituted forKrunicat 67'minutes
- 10PjanicBooked at 30minsSubstituted forBajicat 83'minutes
- 11DzekoBooked at 51mins
- Pavel Kralovec
- Shots on Target
Second Half ends, Northern Ireland 1, Bosnia and Herzegovina 2.
Corner, Bosnia and Herzegovina. Conceded by Craig Cathcart.
Attempt saved. Jamal Lewis (Northern Ireland) header from the centre of the box is saved in the bottom left corner. Assisted by Steven Davis with a cross.
Corner, Northern Ireland. Conceded by Edin Dzeko.
Goal! Northern Ireland 1, Bosnia and Herzegovina 2. William Grigg (Northern Ireland) right footed shot from very close range to the top right corner. Assisted by Liam Boyce following a corner.
Corner, Northern Ireland. Conceded by Gojko Cimirot.
Attempt missed. William Grigg (Northern Ireland) right footed shot from the left side of the box misses to the left. Assisted by Stuart Dallas with a cross.
George Saville (Northern Ireland) wins a free kick in the defensive half.
Foul by Rade Krunic (Bosnia and Herzegovina).
Attempt blocked. Steven Davis (Northern Ireland) right footed shot from outside the box is blocked.
Corner, Northern Ireland. Conceded by Rijad Bajic.
Attempt blocked. William Grigg (Northern Ireland) header from the centre of the box is blocked. Assisted by Liam Boyce with a headed pass.
Corner, Northern Ireland. Conceded by Ervin Zukanovic.
Delay over. They are ready to continue.
Delay in match Ibrahim Sehic (Bosnia and Herzegovina) because of an injury.
Foul by George Saville (Northern Ireland).
Ibrahim Sehic (Bosnia and Herzegovina) wins a free kick in the defensive half.
Corner, Northern Ireland. Conceded by Ervin Zukanovic.
Attempt saved. Liam Boyce (Northern Ireland) right footed shot from the centre of the box is saved in the centre of the goal.