Atletico Madrid secured their first Champions League victory of the season after defeating Manchester United 2-0 at the Riyadh Air Metropolitano on Tuesday night.
Pablo Barrios gave Diego Simeone's side a dream start inside the opening minute before substitute Ademola Lookman sealed the result late on, shortly after Manchester United defender Leny Yoro was sent off.
United barely had time to settle before falling behind after just 47 seconds.
Alex Baena drove forward on the counter-attack and carried the ball into the penalty area before cutting it back for the unmarked Barrios, whose deflected finish beat Senne Lammens to put Atletico ahead.
Manchester United responded positively and almost equalised in the 12th minute when Bryan Mbeumo worked his way into the area before sending his effort narrowly wide of the post.
Mbeumo threatened again shortly afterwards following a combination with Youri Tielemans, but Atletico captain Jan Oblak produced a strong save to deny the forward from close range.
The hosts then came close to doubling their advantage when Alejandro Grimaldo curled a free kick against the crossbar.
Atletico thought they had found a second goal just before half-time when Johnny Cardoso fired home from inside the area, but VAR ruled the effort out because Marcos Llorente had handled the ball during the build-up. Pasted text
Simeone's side therefore went into the interval with a 1-0 advantage, while United remained in the contest despite struggling to consistently threaten Atletico's defence.
Atletico continued to create the better opportunities after the restart and Julian Alvarez struck the post with a first-time volley in the 54th minute.
United captain Bruno Fernandes nearly produced an equaliser three minutes later when Tielemans picked him out, but his delicate finish dropped narrowly wide.
Fernandes went even closer in the 70th minute, curling a superb effort against the crossbar as United briefly increased the pressure on their hosts.
Their hopes of mounting a comeback suffered a major setback four minutes later.
Jonathan David raced through the middle before being brought down by Yoro. Following a VAR review, the referee was sent to the pitchside monitor and upgraded the decision to a red card for denying a goalscoring opportunity. Pasted text
Atletico quickly made their numerical advantage count.
David's low strike was saved by Lammens in the 79th minute, but Lookman reacted quickest to the rebound and fired home from close range to make it 2-0.
United were unable to recover, although substitute Matheus Cunha came close to scoring against his former club in stoppage time when Oblak denied his powerful effort.
Atletico held on comfortably to secure all three points and their first Champions League win of the campaign, while Manchester United suffered their first European defeat of the season.
Simeone's side finished with an expected goals figure of 1.42 from 11 attempts compared to United's 0.98, with Barrios' early breakthrough and Lookman's late finish proving decisive.
