How do I get back to QC via Espana from Ongpin?

I am not well versed in that area and the last time we ate at the President's restaurant, we were a convoy so I just followed. The route that I could remember was we went straight till we reached Plaza Sta. Cruz and I couldn't recall the next directions. After some turns and a bridge, I noticed that the road was already merging with Quezon Blvd en route to Manila Hotel. Someone told me that if I wanna go back to QC, I should go under the bridge.