Build CD boots first, then go for Spirit Visage. After this, start jungling like mad and farming minions like mad, your CD (especially if you have CD runes) will be amazing and you'll be able to get gold very quickly. Get Brutalizer ASAP after this and continue farming. You will be pretty bursty atm, but now you gotta make a decision depending on the enemy team and how well are you doing.
Did you get a couple of kills? Are they high physical DPS? For safety I go for GA, but if you are doing ok I'd go and shoot for a Giant's Belt. Upgrade the Brutalizer, then upgrade the Belt into Mallet. Bam, you shall be one bursty mofo at this time. But remember, at this point in the match if you're not dominating you will be focused and die very fast. This is why I like to build GA before Belt/Y Blade because I can be risky.