LISBON, Feb. 21 (Xinhua) -- Andriy Shevchenko scored in the 16th minute to award Chelsea a 1-1 away draw against manager Jose Mourinho's former club Porto in their European Champions League first knockout round, first leg tie on Wednesday.

    The Ukraine striker found the net four minutes after midfielderRaul Meireles put the Portuguese league leaders ahead.

    The English champions lost central defender John Terry to injury in the eighth minute when the England captain collapsed after turning his right ankle. He was carried off on a stretcher.

    Porto capitalised on the gap in Chelsea's defence as former Tottenham Hotspur striker Helder Postiga dribbled into the box and Claude Makelele cleared the ball but only as far as Meireles.

    The midfielder hit the ball high on the volley from 20 metres and it skimmed off Chelsea's Frank Lampard into the corner of PetrCech's net.

    Mourinho reacted by sending midfielder Michael Essien into central defence and bringing on fleet-footed Dutch winger Arjen Robben.

    Robben made his presence felt immediately when he collected the ball 40 metres out, wrong footed Porto's defence and sent Shevchenko through to shoot low past keeper Helton.

    It was eventful end-to-end stuff in the first half. Cech saved Chelsea in the 20th minute when he blocked a point-blank shot from Lisandro Lopez.

    Mourinho was forced to substitute Robben at halftime after the Dutchman suffered a muscle problem. Nigerian John Obi Mikel came on and helped smother the danger from Quaresma.

    Chelsea's top scorer Didier Drogba hit the post in the 77th minute after a fine move from Shevchenko but, with heavy rain falling, second half chances were few and far between at either end.

    Mourinho, who led Porto to Champions League glory in 2004 before being lured to Chelsea by billionaire owner Roman Abramovich, last visited the Dragon stadium with Chelsea two seasons ago in the group stage. Chelsea had already qualified and lost 2-1 after winning the home game 3-1.