Got attacked by a great Dane ... brave or plain dumb to take on a fully grown husky ?

iv got a 6 month chocolate lab and i was walking her 1 day and we went into a dog park and i saw a great dane (fully grown) and off lead and she looked at it and the dane started to bark and ran at her . my lab ran behind me and the dane ran behinde me and clawed her ear , her ear healed in time and i took her out again and we walked past a husky and she looked at it and the husky which was on a lead started to bark and my lab ran behind me again but befor i could turn round to calm her down she ran from behind me really fast and she twisted her lead and befor i could stop her the handle sliped out of my hand and she ran upto the husky and she started to bite and claw it and growling ... whats the matter with her ? shes fine when i take her to college with other poeple and other dogs like bull mastiffs , golden retivers ... p.s. sorry about the spelling mistakes , mine isernt that good