Two second half goals condemned Boro to defeat at the hands of Blackpool.
A Marvin Ekpiteta strike and an own goal proved decisive in turning the scoreline around after Marcus Tavernier had given Boro an early advantage in the contest.
Boro boss Neil Warnock had named an unchanged team from the one which beat Nottingham Forest in midweek to pick up a first away win of the season.
That meant home debuts for Onel Hernandez, Andraz Sporar, and James Lea Siliki, and all three were impressive on their first Riverside appearances.
And it was Lea Siliki who played a major part in Boro’s opening goal after just eight minutes. He picked out Dael Fry with a great delivery to the far post and his header back across goal was met by Tavernier, who slammed the ball home.
Tavernier did well to work an opening himself when he had a shot saved and he also teed up Sporar, whose first-time strike smashed against the angle of the post and the bar. It would have been some way to open his account on home soil.
Tyreece John-Jules had a great chance for Blackpool in both halves, he blazed the first one over from close range and his second opportunity came when he headed a Dujon Sterling cross wide of the mark.
Boro were dealt a blow shortly before the hour-mark when Anfernee Dijksteel pulled up clutching a hamstring, and he was replaced by Isaiah Jones.
The woodwork came to Boro’s rescue when played resumed with a corner after Dijksteel left the field. Luke Garbutt delivered a speculative cross into the box which Joe Lumley failed to convert, but Shayne Lavery couldn’t convert with the goal at his mercy and he shot against the post.
Blackpool were level on 62 minutes though after a controversial free-kick was awarded. Richard Keogh swung the ball into the box and it was held up for Marvin Ekpiteta, who turned and applied the finishing touch to make it 1-1.
Sporar was denied by some good goalkeeping from Chris Maxwell after a great ball from Hernandez as Boro rallied to back in front in the game.
But it was the visitors who stole the advantage with 12 minutes remaining when a corner was flicked on to take a wicked deflection off the unfortunate Grant Hall and into the back of the Boro net.
Boro were almost level within three minutes, substitute Martin Payero coming within a whisker of opening his account for the club when he hit the bar with a strike which had keeper Maxwell grasping thin air.
There were some late attacks both ways as the clock ticked down, but it was the visitors who pocketed the three points.
Boro: Lumley, Dijksteel (Jones 56) Hall, Fry, Tavernier, Hernandez, Sporar, Peltier, Howson (Ikpeazu 87), Lea Siliki (Payero 80), Crooks.
Subs: Daniels, Watmore, Olusanya, Bamba.
Blackpool: Maxwell, Wintle, Anderson, Bowler, Dougall, Lavery (Yates 86), Ekpiteta, Keogh, John-Jules (Madine 71), Garbutt, Sterling.
Subs: Grimshaw, Connolly, Husband, Gabriel, Carey.
Referee: David Webb
Att: 21,022 (1,131 Blackpool)