VIDEO: Wolfsburg opens scoring vs. United thanks to Valencia's awful defending

Manchester United's first home fixture in the Champions League since 2013 got off to a rough start following a defensive blunder that saw the hosts begin the match with a one-goal deficit three minutes after kick-off.

As VfL Wolfsburg hovered around the United box, putting together a string of passes, Max Kruse found a surging Daniel Caligiuri beyond the English side's back line.

Caligiuri would have been offside had Antonio Valencia not miserably failed to join his teammates in playing the offside trap, subsequently affording the Wolfsburg midfielder acres of space to open the scoring.