BOLTON - El-Hadji Diouf made up for his disappointment in the African Nations Cup by giving Bolton the edge in the UEFA Cup.
The Senegal striker left Ghana early after his side failed to make their expected impact.
But the smile was back on his face at the Reebok Stadium as he gave Bolton a slim advantage going into the second leg of the last-32 encounter in Spain next week.
He scored the winner in the 74th minute, 60 seconds after Atletico substitute Sergio Aguero was sent off, apparently for spitting.
Bolton richly deserved the victory and Matt Taylor was outstanding.
After missing a sitter the defeat by his former club Portsmouth at the weekend, the midfielder grew in confidence as the night progressed.
He almost made the breakthrough in the first minute when the recalled Nicky Hunt delivered a cross from the right.
Taylor peeled away from his marker but goalkeeper Christian Abbiati saved his header on the line.
Then Taylor came close in the fourth minute when Abbiati parried his effort at the post.
Taylor was finding room to manouvre and chipped a shot over the bar in the 10th minute after Kevin Davies chested the ball back to him.
Diouf then sparked a brief melee when he bundled Simao into touch in the 14th minute.
After order was restored Jose Antonio Reyes sent the free-kick into the area and Antonio Lopez thought he had scored with a header.
However goalkeeper Jussi Jaaskelainen reacted superbly and pushed the ball over the top.
Taylor then rattled in a shot in the 17th minute that stung the goalkeeper's fingers.
Bolton again came close to making the breakthrough in the 23rd minute when Davies turned quickly only to send his effort narrowly wide of the post.
Atletico broke out of their slumber to launch a swift counter attack in the 38th minute when Simao raced forward.
He tried his luck on goal from 25 yards but his effort went wide of the post.
After a quiet spell Taylor suddenly sparked into life again on the stroke of half-time.
He rattled in a shot from the edge of the area that the goalkeeper parried to safety.
Bolton were being backed by their biggest crowd of the season - 26,163 - and expectation was high at the start of the second half.
Taylor took advantage of being unmarked to test Abbiati in the 50th minute with a low drive from 25 yards.
Then a minute later Danny Guthrie strode forward but his effort from distance lacked power.
Diego Forlan came close to breaking the deadlock in the 54th minute with a neat bit of skill.
He worked his way into the area, only to send his shot into the side netting.
Atletico poured forward in the 65th minute, only for Maxi Rodriguez to slice the ball nearer to the corner flag than the goal.
It was brief respite for the visitors, however, with Bolton launching a swift counter attack.
Skipper Kevin Nolan's finish was wasteful, going high over the bar.
The game took a dramatic twist in the 73rd minute when Aguero was sent off, apparently for spitting, after a challenge on Taylor.
Bolton immediately took advantage and scored the winner a minute later when Diouf scored his fifth goal of the season after good work from Stelios Giannakopoulos and Taylor.
Atletico tried hard to get back in the game but Bolton held on and will go to Spain next week in good heart.
