A penalty from Alan enabled SC Braga to end Liverpool FC's unbeaten UEFA Europa League run this season, earning the Portuguese club a narrow lead when the round of 16 tie concludes next week.
Alan punished Sotiris Kyrgiakos's trip on Mossoró after 18 minutes of an encounter which the hosts controlled before the break. Although Liverpool perked up in the second half, particularly after the introduction of club-record signing Andy Carroll, they seldom looked like scoring what would have been only their second away goal in the competition proper this term.
Following a quiet opening, any designs Liverpool had of a fourth successive European clean sheet evaporated when Mossoró's sharp turn drew a foul from Kyrgiakos and Alan tucked away Braga's 100th goal in UEFA competition. Domingos Paciência's men were on their way to adding the Merseysiders' scalp to those of Celtic FC and Arsenal FC.
If that partly stirred Liverpool into action, the Reds' response remained muted. Without the injured Steven Gerrard and the ineligible Luis Suárez, Kenny Dalglish's side were struggling to recapture the fluency which had characterised their weekend victory against Manchester United FC.
Braga, meanwhile, were asking all the questions in attack and but for the woodwork would have doubled their advantage before the interval, Sílvio rattling the crossbar with a left-footed strike from distance. Liverpool's response was limited to a tame header from Raul Meireles which goalkeeper Artur fielded comfortably.
The early phase of the second period brought little change for the visitors, prompting the introduction of Carroll for his European debut in Liverpool red. The burly forward's appearance almost paid immediate dividends as his glancing header set up Dirk Kuyt, who was thwarted by the sliding Artur, and moments later the €40.25m January acquisition had an effort deflected wide.
Suddenly it was the English team threatening, with Kuyt chesting down Meireles's pass on the edge of the box, spinning and forcing Artur into a fingertip save. Despite late pressure, Braga held firm, setting up an intriguing return leg in seven days' time.