Just over 12,000 supporters were in attendance to for the visit of Man City
By Les Roopanarine
Manchester City edged past a spirited Middlesbrough side to maintain Roberto Mancini's unblemished record and book a place in the FA Cup fourth round.
Benjani broke the deadlock on the stroke of half-time when he swept home an incisive pass from Martin Petrov.
Boro impressed with their workrate and commitment, but struggled to create.
Their attacking play improved after the break, however, with Rhys Williams heading over their best chance as City likewise wasted several opportunities.
The win maintains City's flawless start under Mancini, who has now guided his side to three wins in three games, with six goals scored and none conceded.
But while Mancini might have racked up 10 Coppa Italia wins as a player and manager, his team selection will have left some onlookers questioning his commitment to the English Cup.
Presumably mindful of Wednesday's first-leg League Cup semi-final against Manchester United, the Italian adopted a conservative approach.
There were five changes to the City line-up, which had Benjani ploughing a lone furrow up front and included a first-team debut for young defender Dedryck Boyata.
Even with City in fine form since he replaced Mark Hughes, it was a risky call by Mancini and on another day it might have backfired.
Boro, labouring 26 places below City on the league ladder, had won only twice in 10 games since Gordon Strachan's late-October arrival on Teesside.
Yet the early exchanges, during which Boro midfielder Adam Johnson was comfortably the best player on the pitch, threatened to make a nonsense of the form book.
Showing levels of commitment and belief that belied their recent Championship struggles, Boro were relentless in their determination to deny City time and space, closing down quickly and launching a series of raids down the flanks.
Strachan's tactics meant that City, unable to build attacking moves through midfield, were reduced to punting long balls forward to Benjani, who cut an increasingly isolated figure.
But an injury to Johnson just after the half hour upset Boro's momentum, and City were quick to exploit their hosts' vulnerability.
The lurking danger was clear when a neat exchange between Petrov and Benjani on the edge of the area culminated with the Bulgaria international slicing a shot wide.
But Petrov soon made amends. From a starting position deep in central midfield, he carried the ball forward before splitting the Boro defence with an inventive ball to Benjani, who fired an angled shot across keeper Danny Coyne.
Mancini, scenting victory, moved swiftly to consolidate City's advantage by introducing Carlos Tevez at half-time.
Nevertheless, the first clear-cut chance after the break fell to Boro's Williams, who should have done better than head tamely over when Tony McMahon's far-post cross from the left found him in space.
A momentary loss of concentration by Chris Riggott subsequently allowed Tevez through, but having rounded Coyne the Argentina international failed to find the net from a tight angle.
Mancini responded by introducing a third attacker in the shape of Craig Bellamy, but Boro - for all their inability to cause problems at the other end - remained resolute.
David Wheater forced Vincent Kompany to head off the line late on, while Bellamy forced a fine injury-time save from Coyne, but City ultimately had to settle for a narrow win ahead of United's midweek visit to Eastlands.
Middlesbrough manager Gordon Strachan on strengthening his squad in January:
"It needs to be done because it is not often you get a situation where at a good club, you have to ask somebody [Marcus Bent] to come back for two weeks to you for a favour.
"That doesn't go on at too many clubs, and that's where we are at the moment.
"We have got a 19-year-old [Jonathan Franks] who just made his debut last week.
"We need to do something for these young ones, because we don't want to push them too early."
Manchester City manager Roberto Mancini:
"It's important. Middlesbrough played very, very well. They were under pressure in the first 20 minutes, but we scored a goal and it went well.
"I am very, very happy. When you start a new job, it is important that you start well. We have started well, but we must work hard in the next week.
90:00+4:13 The game is over, as the referee blows his whistle.
90:00+3:46 Gary O'Neil restarts play with the free kick.
90:00+3:46 Booking Gareth Barry goes into the book.
90:00+3:40 Gareth Barry is adjudged to have handled the ball.
90:00+2:33 Foul by Jonathan Franks on Pablo Zabaleta, free kick awarded. Shay Given restarts play with the free kick.
90:00+2:11 Foul by Gareth Barry on Justin Hoyte, free kick awarded. Direct free kick taken by Gary O'Neil.
90:00+1:40 Effort on goal by Martin Petrov from just inside the penalty area goes over the target.
90:00+1:11 Craig Bellamy takes a shot. Save by Danny Coyne.
89:56 Free kick awarded for an unfair challenge on Jonathan Franks by Gareth Barry. Gary O'Neil takes the free kick.
89:19 Carlos Tevez gives away a free kick for an unfair challenge on David Wheater. Indirect free kick taken by Gary O'Neil.
87:48 Gareth Barry gives away a free kick for an unfair challenge on Luke Williams. Gary O'Neil restarts play with the free kick.
83:51 Gary O'Neil challenges Silvio Sylvinho unfairly and gives away a free kick. Indirect free kick taken by Shay Given.
82:36 Jonathan Franks is ruled offside. Free kick taken by Shay Given.
81:15 Corner taken left-footed by Martin Petrov from the right by-line, Marcus Bent manages to make a clearance.
79:19 Free kick awarded for an unfair challenge on Carlos Tevez by Chris Riggott. Direct strike on goal from the free kick comes
in from Carlos Tevez.
76:54 Free kick awarded for an unfair challenge on Pablo Zabaleta by Jonathan Franks. Shay Given takes the free kick.
73:22 Substitution (Man City) makes a substitution, with Craig Bellamy coming on for Vladimir Weiss.
71:24 Outswinging corner taken by Gary O'Neil from the right by-line. Outswinging corner taken by Gary O'Neil from the right by-line,
Shot from deep inside the area by Tony McMahon clears the crossbar.
69:50 Danny Coyne takes the free kick.
69:50 Substitution (Middlesbrough) makes a substitution, with Luke Williams coming on for Julio Arca.
69:50 The assistant referee flags for offside against Benjani Mwaruwari.
68:07 Direct free kick taken by Marcus Bent.
68:07 Booking Javier Garrido booked for unsporting behaviour.
67:40 Unfair challenge on Mark Yeates by Javier Garrido results in a free kick.
65:42 Carlos Tevez produces a right-footed shot from just outside the box that misses to the right of the target.
63:19 Centre by Tony McMahon, Header on goal by Rhys Williams from inside the box goes harmlessly over the target. Effort from the
edge of the box by Carlos Tevez goes wide of the right-hand upright.
62:04 Inswinging corner taken right-footed by Gary O'Neil, clearance by Vincent Kompany. Corner from right by-line taken by Gary
56:57 Carlos Tevez takes a shot. Save made by Danny Coyne.
56:07 Pablo Zabaleta takes the direct free kick.
56:07 Substitution Mark Yeates replaces Marvin Emnes.
56:07 Gary O'Neil concedes a free kick for a foul on Pablo Zabaleta.
Correction - 48:12 Foul by Gary O'Neil on Vladimir Weiss, free kick awarded. Carlos Tevez restarts play with the free kick.
48:12 Gary O'Neil gives away a free kick for an unfair challenge on Vladimir Weiss. Gareth Barry takes the free kick.
46:42 Booking Gary O'Neil booked.
45:11 Jonathan Franks gives away a free kick for an unfair challenge on Vladimir Weiss. Carlos Tevez takes the free kick.
45:01 The second half kicks off.
45:01 Substitution Carlos Tevez is brought on as a substitute for Nigel De Jong.
45:01 Substitution Gareth Barry on for Micah Richards.
45:00+1:17 The whistle is blown to end the first half.
44:56 The assist for the goal came from Martin Petrov.
44:56 GOAL - Benjani Mwaruwari:Middlesbrough 0 - 1 Man City Goal scored by Benjani Mwaruwari from just inside the penalty area to the bottom left corner of the goal. Middlesbrough 0-1
43:59 Shot from 30 yards from Vladimir Weiss. Blocked by Chris Riggott.
40:35 Free kick awarded for an unfair challenge on Rhys Williams by Javier Garrido. Direct free kick taken by Chris Riggott.
38:14 Effort from the edge of the area by Martin Petrov goes wide of the left-hand post.
36:18 Benjani Mwaruwari gives away a free kick for an unfair challenge on Chris Riggott. Julio Arca takes the direct free kick.
34:59 Pablo Zabaleta gives away a free kick for an unfair challenge on Marvin Emnes. Gary O'Neil takes the direct free kick.
32:14 Chris Riggott fouled by Benjani Mwaruwari, the ref awards a free kick. Chris Riggott takes the free kick.
31:22 Substitution Marvin Emnes replaces Adam Johnson.
29:15 Free kick awarded for an unfair challenge on Vincent Kompany by Rhys Williams. Free kick taken by Vincent Kompany.
25:36 The referee blows for offside. Free kick taken by Micah Richards.
24:10 Free kick awarded for a foul by Adam Johnson on Silvio Sylvinho. Free kick taken by Javier Garrido.
23:33 Pablo Zabaleta concedes a free kick for a foul on Jonathan Franks. Justin Hoyte takes the free kick.
22:23 Tony McMahon takes a shot and went wide right of the goal.
21:24 Julio Arca concedes a free kick for a foul on Nigel De Jong. Vincent Kompany restarts play with the free kick.
20:29 Unfair challenge on Tony McMahon by Martin Petrov results in a free kick. Danny Coyne restarts play with the free kick.
18:46 Dedryk Boyata concedes a free kick for a foul on Marcus Bent. Free kick crossed left-footed by Adam Johnson from right wing,
Micah Richards manages to make a clearance.
18:03 Free kick awarded for a foul by Rhys Williams on Vincent Kompany. Shay Given restarts play with the free kick.
17:21 Corner taken by Adam Johnson from the left by-line, Dedryk Boyata makes a clearance.
14:48 Marcus Bent is caught offside. Nigel De Jong takes the indirect free kick.
7:25 Benjani Mwaruwari gives away a free kick for an unfair challenge on Tony McMahon. Tony McMahon takes the direct free kick.
6:58 Inswinging corner taken right-footed by Vladimir Weiss from the left by-line, Justin Hoyte manages to make a clearance.
6:41 Pablo Zabaleta takes a shot. Tony McMahon gets a block in.
6:01 Martin Petrov takes a inswinging corner.
3:58 Free kick awarded for a foul by Justin Hoyte on Vladimir Weiss. Free kick taken by Vladimir Weiss.
3:29 Martin Petrov handles the ball and concedes a free kick. Free kick taken by Tony McMahon.
2:50 Vincent Kompany gives away a free kick for an unfair challenge on Marcus Bent. Gary O'Neil takes the direct free kick.
0:27 Free kick awarded for an unfair challenge on Adam Johnson by Vladimir Weiss. Julio Arca takes the direct free kick.
0:00 The match begins.
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