Germany winger Marco Reus claimed a hattrick on his comeback as Borussia Dortmund hammered Legia Warsaw 8-4 on Tuesday in a record Champions League result which yielded seven first-half goals.

It was the first time a Champions League game has had a 5-2 half-time scoreline since Monaco ended up beating Deportivo de La Coruna 8-3 in November 2003.

The 12-goal haul in Dortmund bettered the record set in the Monaco-Deportivo game of 11 goals for a Champions League game.

With Dortmund already through to the last 16, the huge win keeps them top of Group F, two points clear of Real Madrid.

Dortmund's Shinji Kagawa and Legia's Aleksandar Prijovic both finished with two goals each thanks to some poor defending by both teams.

Reus, who captained Dortmund, made his return after 185 days out with an adductor injury which ruled him out of June's European championships.

It was his first match since Dortmund lost the German Cup final to Bayern Munich on penalties in Berlin on May 21.

Tuchel made nine changes to his starting line up after admitting his side looked tired mentally and physically from Saturday's 1-0 win over Bayern Munich.

Only defenders Marc Bartra and Matthias Ginter kept their places in Dortmund's starting line-up.

The match got off to an explosive start.

Legia took an early lead when Prijovic was given too much space in the area to chip his shot home and stun the Dortmund crowd on 10 minutes.

But Borussia roared back with five goals in 16 minutes.

Their first three goals came in 198 seconds when Kagawa headed home on 17 minutes, then slotted a second just a minute later.

To compound Warsaw's problems a clearance punch from goalkeeper Radoslaw Cierzniak clattered off Nuri Sahin's chest and into the Legia goal to make it 3-1 on 20 minutes.