Riyad Mahrez misses a penalty but Man City go level with Borussia Dortmund.

Manchester City secured top spot in Group G after a virtually seamless 0-0 draw Borussia Dortmund at Signal Iduna Park.

City came closest to breaking the deadlock when Riyad MahrezA second-half penalty was converted and they remain unbeaten and secure top spot in Group G with one game in hand.

A point was also enough for Dortmund, who were determined to keep a clean sheet after winning the first half and are also guaranteed a place in the last 16.

Erling Holland had little chance to make an impact on his former club and was substituted at half-time.

Guardiola handed goalkeeper Stefan Ortega his debut for the club and the England defender John Stones returned to action for the first time in seven matches after recovering from a hamstring injury.

Nathan Ake, Ilkay Gundogan, Julian Alvarez and Phil Foden also returned to the starting lineup, and Ederson, Kevin de Bruyne, Jack Grealish, Bernard Silva, Manuel Akanji and Aymeric Laporte everyone rested.

With City already assured of their place in the knockout stages and a good enough score to see off Dortmund, the opening exchanges lacked any real pace.

City goalkeeper Ortega made his first save with his feet in the 16th minute when Karim Adeyemi was left onside to shoot home.

Adeyemi was again instrumental as Dortmund began to stretch City’s back, first picking out Giovanni Reina on the left of the area after a flowing move, but Ortega did well to keep out the latter’s effort.

Germany forward Adeyemi then produced a wonderful low cross into the path of Yusufah Mukoka, who allowed the ball to run past him before flying wide.

Teenage striker Mukoka teamed up with Adeyemi again and forced Ortega into another save.

City had 66 per cent of possession in the first half but never troubled Dortmund goalkeeper Gregor Kobel as Nathan Ake sent a lofted header from Phil Foden’s free-kick just before the break flying over the crossbar.

Dortmund were the first to threaten after the restart Jude Bellingham failed to connect properly with his shot into the area before City spurned a chance to take the lead after being awarded a penalty in the 57th minute.

Mahrez went down under a rash challenge from Emre Can, but the City winger’s subsequent spot-kick was comfortably saved by Kobel, to the delight of the home crowd.

City continued to dominate possession and began to pose a greater threat as Alvarez’s first volley was saved by Kobel.

But with the scoreline enough to see both teams go ahead, there was little need in the closing stages and neither side created more chances.