One team wanted to spoil; the other wanted to play. While Atlético Madrid were determined to make the contest as dull as possible, Thomas Tuchel gave Chelsea freedom to express themselves. Liberated, Chelsea stood up to be counted. They refused to rise to Luis Suárez’s provocation and they punished Atlético’s grinding negativity under Diego Simeone when Olivier Giroud, with a bit of help from VAR, came up with a special goal midway through the second half. Tuchel could celebrate the perfect away performance in Europe and his most impressive win since replacing Frank Lampard last month. Chelsea were solid and professional at the back after recovering from a slow start, they were mature and precise in midfield and they were inspired when their first clear sight of goal arrived, Giroud’s astonishing overhead kick ensuring they left Bucharest with a slender advantage. Atlético could have no complaints after ceding the initiative to Chelsea, who were by far the more progressive side. Andreas Christensen shone in the absence of Thiago Silva in the middle of the back three, limiting La Liga’s pacesetters to few opportunities, while Callum Hudson-Odoi was a positive at right wing-back after being subbed on and off against Southampton last Saturday. Atlético barely created anything and their frustration was epitomised by Suárez embarking on a solitary wind-up mission as the match wore on, testing Chelsea with his niggles off the ball and squaring up to Antonio Rüdiger at one stage. Rüdiger refused to be drawn in and Chelsea, who have a wonderful chance of progressing beyond the last 16 for the first time since 2014, focused on letting their superior football do the talking. Tested by Atlético’s stifling tactics, they stayed calm. Mason Mount was outstanding despite picking up a booking that rules him out of the second leg on 17 March and Giroud, an unused substitute against Southampton, was ruthless with his only chance. Chelsea had excellent performances across the pitch, with Jorginho and Mateo Kovacic dictating play in midfield. They will know, though, that it is not over yet. Jorginho is also suspended for the return game and Atlético, who were denied home advantage because of Covid-19 restrictions, will be dangerous and cunning at Stamford Bridge, particularly if they give the lively João Felix more help in attack. It was Felix who inconvenienced Chelsea most. Jorginho and Mount were booked for fouling the young forward, who threatened with an overhead kick in the second half and was the only Atlético player who wanted to run with the ball. Simeone’s smothering tactics were hard to understand given that Chelsea were skittish during the early stages. Mount was booked for chopping Felix down in the first minute and Édouard Mendy almost gifted Saúl Ñíguez a calamitous goal after dithering with a backpass. Chelsea’s goalkeeper got away with it. Soon, though, Tuchel was remonstrating with Rüdiger and Marcos Alonso after they left a bouncing ball to each other on the right. Suárez nipped in, stealing possession before crossing for Thomas Lemar to poke wide with Mendy stranded. It was a reminder, not that one was needed, that Chelsea could not afford to relax with Suárez around. Yet they soon settled down. Hudson-Odoi was diligent in his defensive work, tracking back to contain Lemar, and dangerous when he linked with Mount. Although Atlético threatened again when Ángel Correa combined with Suárez just before half-time, they often defended with a back six. Chelsea had 71% possession in the first half, though creating chances was difficult. Timo Werner had their best moment, darting in from the left before testing Jan Oblak. Once again Tuchel found himself craving more precision in the final third. Chelsea were running down dead ends and there always seemed to be a red and white shirt in the way. Atlético, organised despite the absence of José María Giménez, compressed the space and it summed them up when Simeone was booked on the touchline. Chelsea had nothing to fear and Mount refused to stop probing. In the 67th minute a cross came into the Atlético area from the left. The ball looped up into the air, Mount challenging Mario Hermoso, who diverted it to Giroud. The 34-year-old produced a moment of genius, using his left foot to beat Oblak with a powerful overhead kick. Although the flag went up for offside against Giroud, a lengthy VAR review confirmed that the final touch came off Hermoso. Chelsea were rewarded for their patience. Atlético were punished for their lack of ambition.