Match ends, Bosnia and Herzegovina 1, Republic of Ireland 1.
The Republic of Ireland maintained their hopes of a Euro 2016 spot after they drew with Bosnia-Herzegovina in the play-off first leg in Zenica.
The game appeared in severe danger of being abandoned after half-time when the pitch became shrouded in thick fog.
However the Republic looked to have snatched victory when Robbie Brady hit a precious away goal on 82 minutes.
But Edin Dzeko levelled three minutes later to leave the play-off in the balance going into Monday's second leg.
Republic manager Martin O'Neill will hope the possible return of Shane Long, Jon Walters and John O'Shea will give them impetus for the Dublin contest.
Southampton striker Long may be available again after injury while O'Neill may also welcome back the influential O'Shea and Walters after suspension.
With the Republic having scored the away goal, a 0-0 draw at the Aviva Stadium will be enough to secure the Irish a finals berth in France.
Frantic finish in the fog after early stalemate
Brady struggled for much of the contest as both he and Republic left-back Stephen Ward found Bosnia right-sided midfielder Edin Visca a handful.
The Norwich winger's goal came in his only piece of attacking play of note as he cut inside Toni Sunuci before beating Bosnia's Chelsea goalkeeper Asmir Begovic at his near post with a shot from 14 yards.
Brady's goal could hardly be seen from the stands such was the fog that had enveloped the Bilino Polje Stadium in Zenica.
At that stage, the Irish - after being second best for most of the contest - looked on course to be in firm control of the play-off going into the second leg.
However, the Republic's left-sided flank was once again exploited three minutes later as Ognjen Vranjes got in behind Ireland substitute James McClean before squaring for Roma star Dzeko to poke past Darren Randolph.
Bosnia boss first-half possession but lack penetration
With Visca a threat from early on, the Republic had a couple of nervous first-half moments as Vedad Ibisevic fired into the side-netting from close range and Senad Lulic then failed to divert an Ervin Zukanovic header past Randolph, when only a touch was needed.
However, Bosnia playmaker Miralem Pjanic struggled to impose himself on the contest while his Roma team-mate Dzeko was well shackled by the impressive Derby defender Richard Keogh.
The Republic scarcely created an attacking opening in the first period but the visitors would still have been the far happier outfit at the interval given their list of absentees.
Fog almost leads to second-half farce
There were few chances at either end in the opening 37 minutes of the second half, with the players perhaps affected by the thick fog that filled the stadium.
Visca continued to be the game's most influential performer but Bosnia manager Mehmed Bazdarevic made the baffling decision to take off the right-sided player with over 20 minutes left.
With that decision, the match appeared likely to peter out into a goal-less draw before Brady pounced on Edin Cocalic's attempted clearance then cut inside Sunjic to fire past Begovic.
The Republic had only eight minutes plus injury-time to hold out but they couldn't manage it as substitute Vranjes managed to get in between McClean and another replacement, Marc Wilson, before finding the unmarked Dzeko on the edge of the six-yard box.
Man of the match - Richard Keogh
In John O'Shea's absence, Derby County's Keogh produced a typically committed display as he and central defensive partner Ciaran Clark largely subdued Bosnia dangerman Dzeko.
Republic of Ireland defender Ciaran Clark: " It was a good performance defensively, but this game is done now and we have to concentrate and get ready for the game on Monday night now.
"We are confident we can go out there and get a result. It's going to be a tough game for both teams for sure, we have got the away goal."
Bosnia coach Mehmed Bazdarevic: "It was difficult to relay instructions to the players in the second half because we could barely see anything at all from the dug-out.
"We are a bit disappointed with the result but I have to admit that we didn't play well, perhaps because we weren't composed enough."
- 13MujdzaSubstituted forVranjesat 51'minutes
- 19ViscaSubstituted forDjuricat 73'minutes
- 16LulicSubstituted forHajrovicat 87'minutes
R. of Ireland
- 17WardBooked at 26minsSubstituted forWilsonat 67'minutes
- 20HoolahanSubstituted forMcCleanat 60'minutes
- 19BradySubstituted forMcGeadyat 86'minutes
- Dr. Felix Brych
- Shots on Target
Second Half ends, Bosnia and Herzegovina 1, Republic of Ireland 1.
Ognjen Vranjes (Bosnia and Herzegovina) wins a free kick in the defensive half.
Foul by James McClean (Republic of Ireland).
Foul by Vedad Ibisevic (Bosnia and Herzegovina).
Seamus Coleman (Republic of Ireland) wins a free kick in the defensive half.
Milan Djuric (Bosnia and Herzegovina) wins a free kick in the attacking half.
Foul by James McCarthy (Republic of Ireland).
Foul by Edin Dzeko (Bosnia and Herzegovina).
Glenn Whelan (Republic of Ireland) wins a free kick in the defensive half.
Attempt blocked. Edin Cocalic (Bosnia and Herzegovina) right footed shot from outside the box is blocked. Assisted by Ognjen Vranjes.
Substitution, Bosnia and Herzegovina. Izet Hajrovic replaces Senad Lulic.
Attempt missed. Milan Djuric (Bosnia and Herzegovina) header from the centre of the box is close, but misses to the right. Assisted by Ervin Zukanovic with a cross.
Substitution, Republic of Ireland. Aiden McGeady replaces Robbie Brady.
Goal! Bosnia and Herzegovina 1, Republic of Ireland 1. Edin Dzeko (Bosnia and Herzegovina) right footed shot from the centre of the box to the centre of the goal. Assisted by Ognjen Vranjes with a cross.
Corner, Bosnia and Herzegovina. Conceded by James McCarthy.
Goal! Bosnia and Herzegovina 0, Republic of Ireland 1. Robbie Brady (Republic of Ireland) left footed shot from the right side of the box to the bottom right corner.
Vedad Ibisevic (Bosnia and Herzegovina) wins a free kick in the defensive half.
Foul by Marc Wilson (Republic of Ireland).
Attempt blocked. Miralem Pjanic (Bosnia and Herzegovina) right footed shot from outside the box is blocked.