After what proved to be a largely facile European jaunt in Bulgaria, Jose Mourinho's side have now taken maximum spoils from their opening two UEFA Champions League games and with Barcelona up next, the English champions are in fine fettle.

Drogba has been Chelsea's outstanding performer this season and in the 39th, 52nd and 68th minute, he proved he has now added a goalscorer's touch to accompany his undoubted power.

Sofia's 18-year-old substitute Maryan Ognyanov gave the scoreline a more accurate reflection when he struck in the final minute but it was Chelsea that were always in control.

The opening 45 minutes proved the old adage that patience is a virtue has pertinence in football, not just life, as Chelsea ground out an advantage over a Sofia side that belied those that branded them cannon fodder prior to kick-off.

In their first ever Champions League clash two weeks ago the Bulgarians crumbled in the Camp Nou but on home soil, with a partisan crowd behind them, Sofia were tidy in possession if lacking an edge in front of goal.

There was nothing fanciful about Mourinho's side but then ruthless efficiency has always been his mantra and so it transpired to be true once more, as in-form Drogba struck the game's opener.

Prior to Drogba's strike and Chelsea had hit both post and crossbar and garnered other opportunities, as Andrei Shevchenko continued his laboured run in front of goal. The Ukrainian's woes were compounded on ten minutes when Zhivko Milanov's rogue elbow drew blood if not a booking from a lenient official.

With Chelsea pressing in the early exchanges Drogba swiveled and shot after John Obi Mikel - on a rare start - had bustled his way through on goal, only for his rising drive to strike the bar and rebound to safety.

Sofia responded with the odd attacking foray of their own but with John Terry in commanding form on his return, they were all too easily repelled, as Chelsea again chipped the woodwork.

Michael Ballack stepped up his languid trot to burst into action with a jack hammer of a shot from 30 yards that Petkov did brilliantly to parry onto the post. Moments later and the German was left to rue a header from just inside the area that drifted a yard or so wide.

With the half drawing to its close and Sofia looking solid enough in keeping out their more illustrious visitors, Drogba struck with a poise that has characterised his performances thus far this term. Petkov again did well to keep out Mikel's angled drive but as the ball spun free, it was the Ivorian quickest to react with a powerful finish from six yards.

Sofia striker Hristo Yovov raised a first moment of real consternation when he headed over after ghosting in between Terry and Ricardo Carvalho but within seven minutes of the restart, Chelsea had firmly dampened Levski's spirit.

Wayne Bridge, who gave benched Ashley Cole something to think about with a lively display, arched a long ball from the left and after taking the ball with a sumptuous touch on his chest, Drogba struck instantly and although Petkov got part of his body behind it, the ball rolled into his goal for Chelsea's second.

With any lingering apprehension rendered redundant by Drogba's second, Chelsea began to enjoy their European excursion and it was made all the better, as he completed a hat-trick in the 68th minute.

Although Frank Lampard was awarded both time and space to line-up his drive from distance, his shot lacked verve but not fortune as it ran into the path of Drogba - who with a precocious touch from close range flicked in his third.

In the remaining 20 minutes Chelsea's defending will not have enthused their coach as Petr Cech needed twice to be at his imperious best to deny the lively Yovov.

Sofia substitute Georgi Ivanov could have given his side a consolation was Cech not equal to his daisy-cutter, while Arjen Robben's cameo off the bench saw the Dutchman hit the side-netting after a slalom run and then head over from less than a yard.

It was, though, substitute Ogyanov that wrote himself into the history books with the first ever goal for a Bulgarian club in the Champions League, with a fine rifled finish in the dying stages, after being played in by a sublime Yovov flick.