Mansfield Town 0 Middlesbrough 2: Lee finds scoring touch at last as errors spoil Mansfield's day

Dearden's side let down by defensive slips after matching lofty Middlesbrough

Mansfield Town's leading goalscorer and most valuable player Michael Boulding, a former professional tennis player, had compared his team's task to facing Roger Federer. Even the Swiss master loses occasionally, as Novak Djokovic proved in Melbourne, but as in tennis an opponent 78 places higher in the rankings tends to come through on the day.

Yesterday, Mansfield suffered the equivalent of a service break after a bright opening and might have pulled it back, but in the end were unable to prevent the seeds progressing.

For a side bottom-but-one of the Football League and therefore in danger of dropping out of it for the first time in their existence, however, the Town showed up remarkably well. Boulding, with 15 goals this season in a struggling team, ran like a true Stag and Stephen Dawson was an energetic midfielder. Unfortunately there were two crucial lapses in defence that gifted goals to a Middlesbrough side who have scored fewer of them than any Premier League team except Derby. Those mistakes tempered the satisfaction of Billy Dearden – at 63, second oldest manager around to Sir Alex Ferguson – who said: "All in all I'm quite pleased with some aspects of our game but I'm very disappointed with the goals we conceded."

Gareth Southgate was just grateful to have seen two go in, especially as the first came from his Korean striker Lee Dong-gook, who has yet to hit the mark in more than 20 League games.

Tuncay Sanli, having livened up the forward line recently, was rested but Mido returned as a second-half substitute for a first appearance since October and the prolific Brazilian Afonso Alves may yet be signed from Heerenveen. Jonathan Woodgate seems likely to depart to Tottenham Hotspur but the evidence is that Middlesbrough would do well served by selling a defender to buy an attacker.

This was a proper FA Cup tie in pitting a Mansfield team that cost a princely £50,000 against opposition with half a dozen players whose acquisition forced that most supportive of chairmen, Steve Gibson, to write a cheque with seven figures on it. At the beginning and end of the first half and for much of the second, the chasm seemed bridgeable. Unfortunately, the home side lost concentration at a bad time, after 15 minutes in which Middlesbrough had looked unsettled by a series of vigorous challenges and flummoxed by the strong wind.

When the visitors finally won a corner, the 39-year-old goalkeeper Carl Muggleton could only prod it out; David Wheater mis-hit his shot but it skewed off a defender to Lee, who knocked in only his second goal in 27 games. Twice Town came close to equalising within a minute. A quick throw-in on the right caught Emanuel Pogatetz out of position and Boulding's strong drive was just touched on to the crossbar by Mark Schwarzer. Before the resulting corner was cleared, the goalkeeper made an equally good one-handed save from Boulding's header.

Middlesbrough suffered unexpectedly badly from having to take off Pogatetz with an ankle injury at half-time and for half an hour Julio Arca, dropping to left-back, was given a runaround. Matthew Hamshaw regularly went past him but he found no one to take advantage of his crosses.

The Premier League side created almost nothing at the other end until, with three minutes to play, a good move spread the play from left to right and George Boateng's cross was headed into his own goal by the unfortunate home captain Jake Buxton. Game, set and match.