Nicolae Dica scored the only goal and Steaua Bucharest beat Middlesbrough 1-0 in the first leg of the UEFA Cup semifinals on Thursday.
Dica scored in the 28th minute when he received the ball at the top of the box with his back to goal, turned quickly, and netted into the top corner.
"I think before the game if you'd said 1-0 we would have taken it," Middlesbrough midfielder George Boateng said. "It could have been better, but we've got a feeling of how they are and we've been in much more difficult positions. You can't say it's going to be easy -- but we're very confident."
Middlesbrough threatened in the ninth minute when James Morrison shot wide from 25m, but Dica missed with a 10-meter bicycle kick two minutes later.
The Steaua striker went close again in the 20th with a header from a corner.
Middlesbrough striker Aiyegbeni Yakubu narrowly missed the target with a powerful low shot from 20m after a counterattack.
Steaua defender George Ogararu almost conceded an own goal in the 41st when his header hit the crossbar. From the corner, Morrison's 10-meter shot was saved by Steaua goalkeeper Carlos Fernandes.
Middlesbrough goalkeeper Mark Schwarzer palmed Dorin Goian's eight-meter shot over the bar in the 55th, and then blocked Dica's attempt eight minutes later
Middlesbrough substitute Massimo Maccarone's 25m shot was fumbled by Fernandes in the 86th.
The second leg is at the Riverside Stadium on April 27.
Schalke hosted Sevilla later Thursday in the other semifinal match.
Jose Mourinho is making history for Chelsea season by season.
After guiding the Blues to their first league title for 50 years last year, he is one point away from making it two in a row.
And Mourinho can take the club closer to its first league and FA Cup double today when his team takes on Liverpool in a semifinal at neutral Old Trafford stadium.
Middlesbrough meets West Ham in the other semifinal at Villa Park tomorrow to decide who else plays in the May 13 final at the Millennium Stadium in Cardiff, Wales.
Mourinho is bidding to complete a full set of honors in England. He has already won the Premier League and League Cup, straight after taking the UEFA Cup, Champions League and Portuguese league and cup with FC Porto.
Chelsea is all but assured of its third league title. It will clinch April 29 if it avoids defeat to second-place Manchester United at Stamford Bridge.
Today's semifinal will be the 10th match between Chelsea and Liverpool in two seasons and, although coach Rafa Benitez's team knocked the Blues out of the Champions League in last season's semifinal, Mourinho has a better overall record with five wins, three draws and a loss. Chelsea has won all four Premier League games between the teams and beat Liverpool 3-2 in last season's League Cup final. In the Champions League, Liverpool has the edge with one victory and three draws.
Chelsea's status as a growing powerhouse was enhanced by reports that Bayern Munich midfielder Michael Ballack agreed a four-year contract with Stamford Bridge starting next season, although there was no confirmation from either club.
By contrast, Liverpool's buildup to the game has been overshadowed by reports that Real Madrid is keen on signing its captain, Steven Gerrard.
The England midfielder was close to moving to Chelsea a year ago but signed a new four-year contract at Liverpool.