LEWIS HARRIS saved two penalties and scored one himself as Merton knocked Lewdown out of the Pickard Cup.
They went through to the semi-finals in a penalty shoot-out when the match finished 4-4 after extra time.
Trailing 2-0 and 4-2, Merton hit back through Brendan Harris, Dan Paddon and Pete McMillan before Liam Brend grabbed a stoppage-time equaliser.
Penalties were needed in the Hutchings Cup too with Stratton United progressing to the last four against Kilkhampton. Goals from Tim Couch, Ed Lloyd and Mike Sibley helped them fight back from 2-0 and 3-2 down for a 3-3 draw.
Morwenstow are back on top of the Hodgson Insurance Kingsley League after Sam Hockin (two), Frankie Abbott and Shane Shadrick scored in a 4-2 win at Lifton.