GARRY MONK admitted his Middlesbrough players paid a heavy price for a “horrible second half” as they crashed to a 3-0 defeat to Derby County.

The Teessiders trailed 1-0 at the break after Matej Vydra opened the scoring, but performed reasonably well as they dominated possession in the first half.

However, the second period was a completely different story, with a succession of individual errors enabling Vydra to complete his hat-trick and ushering Derby back into the play-off places as Boro’s expense.

Daneil Ayala conceded a penalty and picked up a deserved red card for two bookable offences, before Ben Gibson and Darren Randolph got themselves into a mess to hand Vydra his hat-trick goal on a plate.

“Talk about shooting yourself in the foot,” said Monk. “It was so disappointing to go from playing that well in the first half, where we played some of our best football of the season.

“The one disappointment of the first half was that we weren’t ruthless enough. With the chances we created, we should have been winning that game at half-time. But the difference was that the one time they were in our half, they were ruthless and clinical with it.

“It was a difficult one at half-time because we had been playing at a good level, and if we had continued playing in that way, you couldn’t see anything else than us getting back into the game and being in a good position to win it.

“But the second half was horrible. We shot ourselves in the foot with individual mistakes and errors. That’s what cost us, and it was bitterly frustrating.”

Monk did not want to criticise Ayala individually, although the Spanish centre-half summed up Boro’s malaise as he conceded a penalty with a rash challenge on Vydra before picking up a deserved second booking for a reckless tackle on David Nugent.

“The whole of the second half was horrible, and it’s been a problem in certain games this season where, like that, we’ve made individual errors and shot ourselves in the foot,” said the Boro boss.

“It’s happened when we could easily have been in a position to win games or pick up points. It’s cost us goals and cost us points. Any team that wants to be successful, or reach its dreams and ambitions, you can’t afford that.”