Mourinho, who guided Porto to the 2004 Champions League title, returned to Portugal for the second time with his new club, and left the Estadio do Dragao in good shape for the return leg on March 6 at Stamford Bridge.

Raul Meireles put Porto on the board after 12 minutes, but his opener was erased by Andriy Shevchenko four minutes later, and the two teams played to a stalemate over the final 70 minutes.

The opening 20 minutes of the match produced much in the way of action, including a pair of goals and a key injury.

Early in the contest Chelsea defender, and team captain, John Terry was forced to leave the game after picking up an injury when his feet got tangled up with Porto's Lisandro Lopez. It was a tough break for the England international, who is just returning from back and calf injuries and is the glue that keeps the Blues back line together.

With Terry sitting on sideline and Chelsea waiting to bring in his replacement, Porto took advantage to move ahead in the 12th minute. Helder Postiga worked his way down the left wing and tried to cross the ball into the middle. However, his cross was blocked by Claude Makelele, who headed the ball out of the penalty area. Meireles was waiting for it 25-yards from goal and volleyed a shot that was headed for the net. The ball took a slight deflection off of Chelsea's Frank Lampard and snuck inside the far post for a 1-0 Porto lead.

Despite the tough break, Chelsea responded well with a goal of its own four minutes later. Arjen Robben, who came on when Terry left the game, made an immediate impact, collecting the ball 30-yards from the net moving into the box. The Dutchman then dropped the ball off to Shevchenko, and the much-maligned striker drove a low shot towards the far post that settled into the lower corner, beating Porto keeper Helton to level the match.

Porto then nearly went back on top in the 20th, but keeper Petr Cech kept the game even. Postiga tried to feed a pass into the box for Lopez, but his pass was deflected. The ball took a fortunate bounce for Porto and ended up on the foot of Lopez, who turned and fired a shot on net. Cech closed out on Lopez quickly, though, and deflected the shot wide.

In the 39th minute, Porto was just inches away from the lead, but was denied by the cross bar. Meireles worked the ball down the left flank and slid a pass to Ricardo Quaresma. The midfielder then sent a dipping shot towards the far post that gave Cech no chance to stop it. The keeper was relieved, however, when the ball slammed off the bar and stayed out.

The second half was played at a measured pace, with Chelsea content to control the ball and mount a counter-attack from time to time. Porto were the more aggressive club, knowing that a draw would favor the Blues in the return leg.

Neither side was able to generate any good chances 30 minutes after the restart, but Chelsea produced a number of long-range efforts to test Helton, and nearly found the net.

In the 77th minute, Shevchenko worked some room for himself 20-yards from goal and held off a defender before firing over the top. Just one minute later, the Blues produced more action inside the box. Didier Drogba was played wide to the left of the goal by Lampard, and the Ivory Coast international drove a hard shot past Helton from close range. However, Drogba was left with a tough angle and his shot caromed off the outside of the post and over the end line.

Porto had the better of the play over the last part of the match, but the Chelsea defense held them off and the Blues will take the 1-1 result back to Stamford Bridge.

In Wednesday's other Champions League action, Liverpool handed defending champions Barcelona a 2-1 defeat at Estadio Camp Nou. Deco put the hosts on top 14 minutes in but Craig Bellamy leveled the match before halftime, and John Arne Riise netted the game-winner in the 74th. In an entertaining contest at the San Siro, Inter Milan and Valencia finished in a 2-2 deadlock. Esteban Cambiasso gave Inter a 1-0 halftime lead, but David Villa pulled the visitors even in the 64th. After Sisenando Maicon gave Inter the lead once more, David Silva equalized four minutes from time to give Valencia a great chance to knock off the favored Italian side in the return leg. Wednesday's other contest saw Lyon and Roma play to a 0-0 draw, leaving their matchup very much on the table when the two teams play the second leg in France.