CHRIS RIGGOTT'S first Premier League goal for three years and another from Tuncay ensured Boro's 11th successive season in the top flight, writes GORDON COX from the Riverside.
Gareth Southgate made three changes from the side which lost at Sunderland seven days ago.
Riggott returned from a loan spell with Stoke City, Mark Schwarzer was back from injury and Fabio Rochemback from a spell on the sidelines. Brad Jones was left out, while Andrew Taylor and Lee Cattermole dropped to the bench.
Portsmouth made four changes as Herman Hreidarsson came in for Lauren, Milan Baros for Kanu, Niko Kranjcar for John Utaka and Arnold Mvuemba replaced Sulley Muntari.
Pre-match entertainment was provided by the band of the Coldstream Guards, while the 2nd Battalion Yorkshire Regiment (Green Howards) received a fantastic reception from Boro and Portsmouth fans as they paraded around the perimeter of the pitch.
Both Tony Adams and Pompey skipper Sol Campbell went out of their way to shake hands of the soldiers, while Southgate also shook hands and posed for photographs as they were presented with a signed Boro shirt.
Portsmouth made a bright start and after a long period of possession won a free-kick just up from the left-hand edge of the Boro penalty area, but David Wheater did well to head clear.
A confident start from the visitors continued and a magnificent 40-yard crossfield pass from Lassana Diarra picked out Mvuemba out wide on the right. He took the ball into the penalty area and pulled it back to Baros, whose shot was blocked by Wheater before Glen Johnson shot wide through a crowded box.
Boro responded, Tuncay won second phase possession inside the Portsmouth box and set up, Alves who brought a smart save from Jamie Ashdown with a low drive from 13 yards.
As both sides probed, chances were limited, but Diarra and Mvuemba caused all kinds of problems and the pair combined to set up Baros with a great chance with 19 minutes played. However, the Czech international blazed well over the bar when in with every chance 10 yards from goal.
Boro stuck to their task and began to cause a few more problems. Stewart Downing headed down to Rochemback but the Brazilian wasted a great chance to shoot first time 12 yards from goal. He elected to bring the ball under control to work a better angle but was quickly dispossessed.
Alves cut into the box in between two defenders but was forced into a quick shot which flew just past Ashdown's left angle.
Boro's tenacity and determination paid off five minutes from the break as Chris Riggott rose unchallenged on the edge of the six-yard box to head home a Rochemback corner.
In first half injury-time Riggott had a chance to make it two as he rose to meet a right-wing Rochemback free-kick, but he couldn't make good enough contact with the ball.
Half-time: Middlesbrough 1 Portsmouth 0
There was a confident start to the second half from Boro, who knocked the ball around well and stretched the visitors, who began to look a little disinterested at times.
The start was built on after 53 minutes as Downing swung over a right-wing corner and Tuncay powered in a header from the edge of the six-yard box for his eighth goal of the season, all in the Premier League.
The second goal injected confidence into Boro, who displayed passing and movement seen at times, but not enough, this season.
Alves made way for Jeremie Aliadiere just past the hour mark, the Brazilian leaving to warm applause.
To serve as a reminder that Portsmouth, given the chance, were still dangerous going forward, Niko Kranjcar eased his way into Boro's penalty area and curled a shot just wide of Mark Schwarzer's left-hand post.
Downing went for glory from distance, but a 30-yard drive was a yard off target.
He was considerably closer to goal when he struck his next shot, which came after a fine build-up involving Rochemback and Tuncay, but a low drive from seven yards was turned round by Ashdown.
Relaxed, Tuncay started to play some of the one touch football which is so eye-catching, while right across the park there was endeavour to match the attitude, no better an example coming in the 88th minute when Wheater produced two fine challenges in as many seconds inside his own penalty area.
It wasn't perfect by any means, but enough sparkle had returned at the right time.
Middlesbrough: Schwarzer; Young, Wheater, Riggott, Pogatetz (Capt), Boateng (Cattermole 88), Rochemback, Arca, Downing, Tuncay, Alves (Aliadiere 61). Unused subs: Turnbull (gk); Taylor, Johnson.
Portsmouth: Ashdown; Johnson, Campbell (Capt), Distin, Hreidarsson, Kranjcar, Diop (Davis 67), Diarra, Mvuemba, Defoe, Baros (Nugent 67). Unused subs: Begovic (gk); Lauren, Hughes.
Referee: Peter Walton, Northampton.
Bookings
Middlesbrough: Arca, 48, foul.
Portsmouth: Diarra, 44, foul.
Attendance: 24,828
Conditions: Warm and sunny with a gentle breeze
Website Boro Man of the Match: Eye-catching from Tuncay, but Chris Riggott was solid throughout.
