Late goals from Nani and Ryan Giggs put Manchester United into the Carling Cup fourth round after Emanuel Pogatetz was sent off at Old Trafford.
United dominated and Cristiano Ronaldo, back for his first start after injury, headed them into a 25th minute lead.
Substitute Adam Johnson volleyed an unlikely second-half equaliser before Pogatetz was given a straight red for a nasty challenge on Rodrigo Possebon.
Veteran Giggs finished coolly and Nani made sure of the win in injury-time. Playing in front of a 53,000 crowd, United started with a strong line-up which including first-team regulars such as Ronaldo, Nemanja Vidic, Giggs, and Wes Brown, along with youngsters such as 18-year-old goalkeeper Ben Amos and 19-year-old striker Danny Welbeck.
The evening was soured after Pogatetz's 66th minute challenge on Possebon, which left the Brazilian prospect being given lengthy treatment before being stretchered off with a suspected broken leg.
But it was Ronaldo, inevitably, who took centre stage as the match kicked-off after Afonso Alves and Stewart Downing threatened early on for Boro without testing debutant Amos.
The Portuguese put United ahead after 25 minutes with a header from a Giggs corner which bore close resemblance to his goal in the Champions League final against Chelsea in May.
United dominated and Cristiano Ronaldo, back for his first start after injury, headed them into a 25th minute lead.
Substitute Adam Johnson volleyed an unlikely second-half equaliser before Pogatetz was given a straight red for a nasty challenge on Rodrigo Possebon.
Veteran Giggs finished coolly and Nani made sure of the win in injury-time. Playing in front of a 53,000 crowd, United started with a strong line-up which including first-team regulars such as Ronaldo, Nemanja Vidic, Giggs, and Wes Brown, along with youngsters such as 18-year-old goalkeeper Ben Amos and 19-year-old striker Danny Welbeck.
The evening was soured after Pogatetz's 66th minute challenge on Possebon, which left the Brazilian prospect being given lengthy treatment before being stretchered off with a suspected broken leg.
But it was Ronaldo, inevitably, who took centre stage as the match kicked-off after Afonso Alves and Stewart Downing threatened early on for Boro without testing debutant Amos.
The Portuguese put United ahead after 25 minutes with a header from a Giggs corner which bore close resemblance to his goal in the Champions League final against Chelsea in May.