Boro were missing 12 first-team players ahead of kick-off and their injury misery was compounded in the first half when Emmanuel Latte Lath failed to recover from a robust challenge before Alex Bangura pulled up with an apparent hamstring strain.
On 31 minutes Cole Palmer had arguably Chelsea’s best chance of the half when Jonny Howson gifted possession straight to the England international, and on his favoured left foot 18 yards from goal, many would have expected the net to bulge rather than the ball to roll wide of the left-hand post.
Mauricio Pochettino’s men were largely dominant in the first 35 minutes without being particularly threatening but it was Middlesbrough who took the lead in the 37th minute through a beautifully crafted goal on the break.
A diagonal ball out from defence by Daniel Barlaser over the top for Isaiah Jones saw the winger hold off the challenge of Levi Colwill before laying the ball across to Hayden Hackney, who neatly applied the finish.
Minutes before the HT whistle, Palmer’s second gilt-edged chance to find the net arrived as Enzo Fernandez’s shot was spilled by Tom Glover but the winger somehow couldn’t level things up from six yards out with the goal gaping.
Pochettino was largely dismissive of domestic cups during his time at Tottenham Hotspur but Chelsea started the second half with added impetus, seemingly well aware of how important an early trophy would be for the manager’s tenure.
First, Mykhailo Mudryk’s whipped effort was held by Glover before Raheem Sterling cut inside to curl a fierce shot just over the bar.
Chelsea’s attacking play has lacked that potent threat in centre-forward positions all season and this display against a spirited Middlesbrough was no different.
Boro are a side Chelsea had beaten nine times in a row before this latest instalment and coming off the back of recording their biggest win of the season so far on Saturday, many thought the Blues would steamroll the depleted hosts.
In truth, Middlesbrough looked largely comfortable and take a deserved, albeit slender, lead to Stamford Bridge for the second leg next week.
Flashscore Man of the Match: Isaiah Jones (Middlesbrough)
