Ivory Coast international Didier Drogba gave Chelsea's Premier League title hopes a boost with a late goal.
Chelsea's record £24million signing finally broke Middlesbrough's resistance nine minutes from time with the help of Frank Lampard, who deserves a share of the credit for a well-rehearsed free kick.
Lampard pulled a free-kick right into the path of Drogba who lethally grabbed his chance with a drive that left goalkeeper Mark Schwarzer helpless.
The goal - and the invaluable three points - were no more than Chelsea deserved. It was astonishing, in fact, that Middlesbrough survived for so long.
Middlesbrough suffered a double blow before kick-off when Chris Riggott suffered a thigh strain and Szilard Nemeth had a stomach upset and were ruled out.
A minutes silence for former Middlesbrough goal hero Brian Clough was immaculately observed by both sets of fans before the kick-off.
Clough scored a record-breaking double century of goals for Boro at the height of his career and a statue could be erected in his memory outside of the Riverside Stadium.
Chelsea dominated the first half but failed to take advantage of their many half-chances. The home side were fortunate however when a Drogba shot struck the bar and bounced back into play with Schwarzer beaten.
The Middlesbrough defence, with 37-year-old Colin Cooper recalled, offered stubborn resistance and Schwarzer brought off some fine saves as Chelsea maintained their superiority. But the home midfield was overrun and their attack offered no threat to the Chelsea goal.
Jimmy Floyd Hasselbaink and Mark Viduka had impressed in the opening games, but the highly-rated strikers were completely ineffective against the strong Chelsea defence.
The second half was delayed slightly when referee Mark Halsey sent Hasselbaink back into the dressing room for a change of shirt. The Dutchman had suffered a gash to his head in the first half that required ten stitches and there was still blood on his shirt.
With no spare Hasselbaink shirt available, the former Blues forward returned to the field with a number four Ehiogu shirt.
Middlesbrough showed a little more attacking enterprise after the break but Petr Cech was still virtually unemployed in the Chelsea goal.
Drogba missed a great scoring chance when he headed a Damien Duff cross over the bar, but he redeemed himself shortly after and Schwarzer had no chance when he crashed the ball into the net after 81 minutes.
Middlesbrough could have no complaints about this defeat and manager Steve McClaren will be hoping for an improved performance when his team face Banik Ostrava in the second leg of their UEFA Cup tie on Thursday night.
Man of the Match Mark Schwarzer defied Chelsea when the London side dominated the first half. The Australian international had no chance with Drogba's goal, just when it looked as though Middlesbrough would hold out.