London,(AP/UNB) – Who needs Diego Costa when you have Davide Zappacosta?On his full Chelsea debut, the wing back announced himself to Stamford Bridge in spectacular fashion with an audacious solo goal eclipsing anything the exiled striker Costa has produced in west London.It was some way, too, for 2012 champion Chelsea to announce its return to the Champions League after failing to qualify last season. Zappacosta’s 30th-minute goal was only the second in a 6-0 rout of Azerbaijani tournament newcomer Qarabag in their opening game in Group C.The deadline-day signing from Torino started the run outside his own penalty area and surged down the field past two defenders before reaching the edge of the Qarabag penalty area where he caught goalkeeper Ibrahim Sehic off-guard with his strike.Asked later if Chelsea had a new hero called Costa, Chelsea manager Antonio Conte replied in a flash: “Zappacosta.”Conte has been trying to avoid questions for months about Diego Costa, who is out of London as he agitates for a move to Atletico Madrid. No wonder Conte was relieved to be talking about Zappacosta, one of five changes from the side that beat Leicester in the Premier League at the weekend.”He played a really good game but now he has to continue to work to improve,” Conte said. “It was his first appearance at Stamford Bridge. It’s not easy to totally change your sporting life in one week, but the answer was very good. He has said he wanted to cross, but he scored and it’s important for us.”For Conte, this was the first chance to see how he can rotate the squad to cope with the demands of domestic and European football. Chelsea was only occupied by domestic duties last season, and it cruised to the Premier League title by seven points.”To play in the Champions League means the coach trusts you,” Conte said. “My message tonight was this. I trust all my players, not only with words but with facts. For the first game in the Champions League I decided to start with rotation.”Also because we have to start the process to improve our players. If we think we can play with 13 players like last season, we are crazy. Instead, we have to improve our players and try to create a good competition between them. A positive competition is very important.”The goals were spread through the team, although the strength of the performance has to be countered with the defensive ineffectiveness of a Qarabag side showing its inexperience.The feeble Azerbaijan champions first conceded after five minutes when Pedro Rodriguez bent the ball past Sehic.Cesar Azpilicueta, playing in a back three, demonstrated his attacking threat when he headed in the third 10 minutes into the second half after being left unmarked to meet Cesc Fabregas’ cross. Just like Zappacosta, Tiemoue Bakayoko marked his Champions League debut for Chelsea with a goal in the 71st minute after coming off the bench.”Baka is improving his physical condition a lot,” Conte said of off-season midfield recruit from Monaco. “He is a strong player, a physical player, and he has to continue to improve and go better in our idea of football. He needs more time than Zappacosta.”Bakayoko turned provider for back-up striker Michy Batshuayi to score his first goal of the season, and the rout was completed when Zappacosta set up Batshuayi for an effort that went in off Maksim Medvedev for an own-goal.”We made a lot of errors,” Qarabag coach Gurban Gurbanov said.Still, Gurbanov was proud to have led an Azerbaijani team into the group stage of European soccer’s elite competition for the first time.Qarabag is a political symbol that goes far beyond football in the country. The club originated in the city of Agdam, a city which has been abandoned since the Nagorno-Karabakh War of the early 1990s. Many locals fled east to the Azerbaijani capital Baku, where Qarabag plays.The largely ruined city is under the control of forces that claim to be local ethnic Armenian separatists but that Azerbaijan alleges include regular troops from the neighboring country of Armenia.”Unfortunately our land is occupied by armed forces,” Gurbanov said through a translator at Stamford Bridge as a post-match news conference took an unexpected diversion into geopolitics. “This makes us stronger.”The game at Stamford Bridge provided all the goals in Group C as Roma and Atletico Madrid drew 0-0 in the Italian capital.