gistfile1.js

            //Initialize the map
            var map = L.map('map',{center: [37.18,-121.72], zoom: 12, drawControl: true, minZoom: 10,maxZoom: 18});

            //terrain, terrain-lines, toner-lite, toner, watercolor
            L.tileLayer(
                'https://mts1.google.com/vt/lyrs=m@231165345&hl=en&src=app&x={x}&y={y}&z={z}&apistyle=s.t%3A2%7Cp.s%3A-100%7Cp.v%3Aoff%2Cp.s%3A-100%7Cp.l%3A14%2Cs.t%3A49%7Cp.v%3Asimplified%7Cp.l%3A15%2Cs.t%3A4%7Cp.v%3Aoff%2Cs.t%3A6%7Cp.l%3A-8&style=47,37%7Csmartmaps',
            {
                subdomains: 'abcd'
            }).addTo(map);

            var polyBig = L.polygon(
                [[37.1631894028733,-121.8016423919471],[37.20107352332477,-121.78945443418344],[37.22322077240998,-121.72834298398811],[37.18110808791507,-121.66997811582405],[37.14950815762241,-121.73709771421272]],
                {color: "red", opacity: 1, fillOpacity: 1});

            var polySmall = L.polygon(
                [[37.17262801853344,-121.76267525937874],[37.20080005987362,-121.75426385190804],[37.191911958397284,-121.71443841245492],[37.1719441004939,-121.72044656064827],[37.1631894028733,-121.74533746030649]],
                {color: "blue", opacity: 1, fillOpacity: 1});

            //Add red
            map.addLayer(polyBig);

            //Add blue
            map.addLayer(polySmall);

            //Blue is now above red

            polyBig.bringToFront();

            //Red is now above blue