Riggott's howler has Derby wailing

Derby County 0 Middlesbrough 1

Schoolboy howlers, as Derby's manager John Gregory calls them, are plunging his side towards relegation. Gregory blamed them for the defeat by Everton in the Rams' previous home game and this time it was a dreadful blunder by the central defender Chris Riggott that handed Robbie Mustoe the only goal of the game.

Mustoe's second goal of the season – his first came in Middlesbrough's 5-1 home win over Derby in November – consigned the Rams to their third successive defeat and their fifth in seven home games.

Their fellow strugglers Ipswich, Fulham and Sunderland are among the visitors to take three points home from Pride Park, so if Derby are relegated it will be largely self-inflicted.

"The nerves kicked in again today," Gregory admitted, "and the pressure's got to a few of the players. But although it was a bad individual error that cost us the goal, it would be wrong to lay the blame on one player – this was the worst team performance I've had in the nine games since I came here."

The state of mind which seems to have enveloped Pride Park was summed up by the only goal. Riggott was under no pressure, when he dallied on the ball just inside the penalty area before striking an intended clearance Mustoe's outstretched leg. The Middlesbrough midfielder volleyed the loose ball into the far corner of the net from 15 yards.

That set the tone for an uninspiring encounter in which Middlesbrough's more methodical approach set them a cut above a Derby side whose main attacking ploy, certainly in the first half, was to hit hopeful balls towards strikers Fabrizio Ravanelli and Branko Strupar. They almost equalised when Ravanelli's 39th-minute headed pass found Rob Lee for the midfielder to drive in a low shot which was saved one-handed by Mark Crossley.

Both strikers were replaced at half-time, but the substitutes Malcolm Christie and Georgi Kinkladze failed to improve matters. The midfielder Paul Boertien had a header saved by Crossley and Kinkladze sent a close-range volley over the bar, but a Derby goal never looked likely.

The visitors, earlier in the season threatened by a relegation fight themselves, were likewise lacking in and around the opposition penalty area, although their manager, Steve McClaren, was more than happy with a victory that took his team into the top half of the table.

However McClaren, who was part of the backroom team at Derby when they moved up to the Premiership in 1996, was sad to see his old club in their present predicament.

"It was a massive three points for us," he said, "but the win is tinged with sadness for me because it leaves Derby in a precarious position. "I believe the appointment of John Gregory was a magnificent move – he is the man to lead Derby back to success, although it may be a bit too late for them now this season.''

An unusually subdued Gregory came close to agreeing with his opposite number. "We have to seriously hope that one or two teams above us get beaten," he said, "we are relying on that now. We've got a real mountain to climb, but anything's possible in football – we've got five games left and I believe we can win them all. I just hope the players believe it too.''

Derby County (4-4-2): Oakes 6; Barton 5, Riggott 3, Higginbotham 5, Zavago 5 (Elliott, 83); Valakari 5, Lee 6, Boertien 5, Morris 5; Ravanelli 4 (Kinkladze, h-t, 5), Strupar 4 (Christie, h-t, 5). Substitutes not used: Foletti (gk), Grenet.

Middlesbrough (4-4-2): Crossley 5; Stockdale 5, Ehiogu 8, Southgate 8, Queudrue 6; Wilkshire 6, Ince 6, Mustoe 7, Greening 6; Whelan 6, Carbone 6. Substitiutes not used: Beresford (gk), Festa, Windass, Marinelli, Johnston.

Referee: P Durkin (Portland) 6.