MANCHESTER (AFP) - Carlos Tevez's second-half header sent Manchester United into a Champions League semi-final clash with Barcelona with a record-breaking 1-0 win over Roma but it was a victory that proved far more painful to secure than it ought to have been.

The English champions' 11th consecutive home win in the tournament took them past the record they had previously shared with Juventus, but this was never a performance worthy of a place in the history books.

Having squandered a string of early chances, United repeatedly looked in danger of conceding a goal that would have given Roma hope of overturning the two-goal deficit they had conceded in last week's first leg in the Stadio Olimpico.

United boss Sir Alex Ferguson admitted he had been relieved to see Daniele de Rossi blast a first-half penalty over the bar.

"We had our moments in the first 25 minutes when their goalkeeper made four fantastic saves," said the Scot. "But obviously the penalty would have made a big difference.

"But it is a European quarter-final and Roma are second in the Italian league. You would expect them to create something."

United will have the advantage of playing the first leg of their semi-final in the Nou Camp and Ferguson promised his side would travel to Catalonia looking to score.

"You have opportunities in life to do something special and I think we have something special in this team.

"Barcelona are a wonderful team but we can't go there and be negative, we have to go there and be positive."

Ferguson's pre-match promises that United would not allow their first-leg lead to affect their approach to the return were somewhat belied by the sight of Cristiano Ronaldo, Wayne Rooney and Paul Scholes taking their place on the bench alongside the hitherto unheard-of Daniel Welbeck.

Ferguson's confidence that he could afford to rest his most valuable assets ahead of Sunday's Premier League meeting with Arsenal was arguably vindicated by the five clear chances his side created inside the first quarter of an hour, although the fact that none of them were taken must have made him pine for the finishing touch that has brought Ronaldo 37 goals already this season.

Park Ji-Sung fired the first opportunity across goal; Carlos Tevez and Wes Brown both failed to find the target with headers from inviting positions and Owen Hargreaves, left with only Doni to beat, saw his shot spin over the bar off the goalkeeper's legs.

Ryan Giggs had been at the origin of most of United's early creativity but the veteran winger was also guilty of the most glaring miss, tamely side-footing straight at Doni from eight yards out after being teed up by the energetic Hargreaves's perfectly-judged cross.

Roma may have been struggling at the back but their forwards were still able to ask questions of a United back four which included both Rio Ferdinand, who passed a late fitness test on his bruised left foot, and Mikael Silvestre, playing for the first time since suffering a serious knee injury in September.

Edwin van der Sar had to get down smartly to keep out shots from Mirko Vucinic and Mancini in quick succession and then enjoyed a kindly bounce of the ball after failing to hold a ferociously struck drive from Simone Perrotta on the half-hour mark.

Moments later, United enjoyed an even bigger let-off, de Rossi blasting his penalty high into the Stretford End after Wes Brown had tripped Mancini.

Unable to rediscover their early zest, United continued to flirt with danger after the interval.

After Silvestre had thrown himself full length to block a shot from Taddei, a collective sigh of relief echoed around the ground as de Rossi's header from the resulting corner found its way into the arms of van der Sar rather than the net.

With just over 20 minutes left however the home supporters were relieved of any lingering tension about the outcome of the evening.

Having again surged down the right flank, Hargreaves sent in a superb cross that Tevez glanced past Doni to earn himself an ovation that was only slightly less enthusiastic than the one accorded to Eric Cantona when the stadium announcer revealed the presence of the United legend at half-time.

The United fans were on their feet again with ten minutes left but that was only to mark club captain Gary Neville's entry to the fray for his first appearance in a United shirt in over a year.