Lautaro Martinez blasts 'immature' Inter after Borussia Dortmund collapse

Lautaro Martinez was far from impressed with Inter's second-half display as it surrendered a two-goal lead at Borussia Dortmund.

Inter striker Lautaro Martinez acknowledges the travelling fans after the full-time whistle.

Lautaro Martinez blasted Inter for its "immaturity" in the second half of its 3-2 Champions League defeat to Borussia Dortmund.

The striker opened the scoring after five minutes at Signal Iduna Park and played a key role as Matias Vecino made it 2-0 shortly before half-time.

Inter, which beat Dortmund 2-0 in Milan two weeks ago, then collapsed in the second 45 minutes, with two goals from Achraf Hakimi either side of a Julian Brandt strike condemning it to defeat.

The result leaves Inter four points behind Group F leaders Barcelona, which it hosts on matchday six, and three adrift of second-placed Dortmund.

Read: Achraf Hakimi leads stunning Dortmund comeback

Martinez is refusing to give up on its hopes of reaching the last-16 but was far from happy with the way the Nerazzurri allowed the match to get away.

"We did well in the first half, but we were a completely different team in the second. We're disappointed because we showed a bit of immaturity in the second half," he told Sky Sport Italia .

"There were mistakes in concentration - these are things that cannot happen, conceding three goals in one half.

"We were missing a bit of maturity in the second half. We have to continue doing well. Hope is not lost."

Vecino conceded Inter defended too deep and did not keep possession well enough in the second half when Dortmund began to increase the pressure.

"It hurts. It's a bad defeat after that good first half," the midfielder said. "We defended too deep in the second half and struggled to keep the ball well.

"Dortmund found courage and enthusiasm after their first goal and everything became very complicated for us. However, there are two more games and we will definitely give it a try."