Goalkeeper Josh Addison saved two penalties as Guernsey FC beat Molesey in a game that saw both teams finish with 10 men at Footes Lane.
Addison first saved from Ashley Lodge before Guernsey's Marc McGrath saw his first-half spot-kick hit the woodwork.
Captain Jamie Dodd fired the Green Lions ahead after the break and Dave Rihoy's effort doubled the lead.
Addison then saved Ross Chalke's spot-kick, which saw Angus McKay sent off, before Molesey's James King saw red.
Guernsey's first win in six matches sees them climb one place to 20th spot in Isthmian League Division One South, five points above the relegation zone.