The Republic of Ireland's hopes of qualifying for the 2018 World Cup were severely dented after falling to a 1-0 home defeat to Serbia.
Aleksandar Kolarov's thumping second-half drive in Dublin was enough to secure all three points for the visitors, who will now have their sights set firmly on Russia next year as they sit four points clear at the top of Group D with two games left.
Ireland's performance was a huge improvement on the underwhelming draw against Georgia on Saturday, but they were comfortably kept at bay by a dominant Serbian side, who played the last 20 minutes with 10 men after Nikola Maksimovic was sent off.
The loss is Ireland's first of the qualifying campaign and leaves Martin O'Neill's men third trailing Wales in second by one point after their 2-0 win over Moldova.
Ireland host Moldova next month before travelling to Wales for what promises to be a mouth-watering occasion.
O'Neill made two changes from the draw against Georgia, with Wes Hoolahan and David Meyler replacing Harry Arter and Glenn Whelan.
Serbia started brightly and inside just two minutes had a clear sight of goal, but Nemanja Matic's low drive from the edge of the box was blocked by Shane Duffy.
Duffy was in the thick of the action again in the ninth minute as he thumped a header past Serbia goalkeeper Vladimir Stojkovic from Robbie Brady's teasing cross. The celebrations were cut short, though, as the Brighton and Hove Albion defender had strayed into an offside position.
Ireland continued to put the Serbian backline under pressure and came close to breaking the deadlock when Shane Long's fizzing drive from distance was well tipped over by Stojkovic.
Former Manchester City defender Kolarov then made an audacious attempt to score from a 40-yard free-kick, but his tame effort crept past Darren Randolph's left-hand post.
Randolph was called into action just minutes later, though, as he got down well to keep out Aleksandar Mitrovic's stabbed close-range effort after a flowing move had carved the Irish defence open.
The half-time break did little to disrupt the frantic pace of the first half as Dusan Tadic tested Randolph within just a minute of the restart, before Long twice squandered two good openings for the hosts.
The deadlock was broken in the 55th minute and came courtesy of a fine strike from Kolarov. Serbia worked the ball across the Ireland box to allow Kolarov's trusted left foot to arrow the ball through Randolph's grasp and off the underside of the crossbar.
Serbia's hopes of seeing the game out comfortably were dealt a blow in the 68th minute when Maksimovic was given a straight red card after a desperate lunge on Daryl Murphy as the substitute was bearing down on goal.
Meyler, James McClean and Cyrus Christie all had efforts as Ireland pushed for an equaliser, but all sailed high and wide of Stojkovic's goal. Murphy came closest to a leveller with five minutes remaining, but his flashed shot from 12 yards was repelled by the Serbian goalkeeper.