The first sentence is correct, and your rewriting of it is not correct, I'm afraid. There's a simple rule here. Verbs of perception - watch, see, hear, listen - are followed by the base form of the verb , regardless of the main tense of the sentence. For example: I saw the two cars crash. = past tense sentence (saw) + base form I'll watch you play football = future tense sentence (will watch) + base form

Your use of "heard" in the second sentence is 听说了 so regardless of whether it is correct or not, it doesn't mean the same thing.