Sam Greenwood’s late goal sent Middlesbrough to the break with high spirits after Middlesbrough suffered their second consecutive 1-0 loss.
Enzo Maresca’s team lost last week to Leeds and Greenwood, on loan from Elland Road to Boro, hit a superb free-kick in the final minutes to help Michael Carrick’s Boro climb to 10th place. They are only two points behind the top six.
Leicester is now top only on goal differential following Ipswich’s victory over Swansea.
For long periods, the Foxes looked like the likely winner at Riverside. However, they could not break through Middlesbrough’s well-organised backline.
In a first half that was hard fought, there wasn’t much between the two teams. Both keepers made brilliant saves.
Leicester controlled possession during the first stages, but Boro created more early opportunities. Josh Coburn, who scored a double in the 3-3 draw with Plymouth last week, twice went close.
The Foxes had two great chances to end the first half deadlock, despite the good work done by the hosts in limiting Leicester.
Maresca’s team almost scored when Kelechi Iheanacho intercepted Isaiah Jones’ attempted backpass, which sting Seny Dieng’s hands.
Dieng denied the leading team again just past the 30-minute mark. He made a brilliant one-handed stop to deny Jannik Vestergaard’s header following a left-side corner.
Mads Hermansen was called upon to save the game in the final seconds of the first period. He first slid to his right to deflect a low Matt Crooks effort around the post. From the corner that followed, he managed to claw out Dael’s header which looked like it was heading for the top right corner.
Leicester had a second-half resurgence and Abdul Fatawu, a substitute who was brought on to replace Stephy Mavididi after a good run down the left flank by the latter, volleyed over from a close range.
Mavididi had his chance, but his shot was pushed wide by Dieng. Iheanacho then got a great opportunity following a Dieng error, and the goalkeeper made amends for his mistake with an excellent save.
Iheanacho’s chip bounced off the post with less than 10 minutes left to play. Boro then scored the winning goal against all odds, just moments after.
The Riverside was initially angry when Oliver Langford stopped play after a Greenwood foul instead of allowing the home team to attack with more men.
Greenwood climbed off the deck and curled a stunning free-kick in Hermansen’s upper corner.