Guardiola furiously approached Lahoz at the half-time whistle with City leading 1-0 on the night but still trailing 3-1 on aggregate.
Minutes before the break officials had wrongly disallowed a second City goal when Leroy Sane was flagged offside despite the ball into the German coming off Liverpool's James Milner.
With City desperate at that point Guardiola was left incensed by the decision and could be seen voicing his opinion to the officials in no uncertain terms.
The Spaniard was visibly angry as he remonstrated with Lahoz, with a red card quickly following.
April 10, 2018