Coming off their road win over the Rams, the Panthers would play their Week 2 homeopener against the Houston Texans. In the first quarter, Carolina pounced first with QB Jake Delhomme hooking up with WR Steve Smith on a 7-yard TD pass and a 12-yard TD pass. The Texans would respond with QB Matt Schaub completing a 31-yard TD pass to WR Andre Johnson. In the second quarter, Houston continued its pounding with Schaub and Johnson hooking up with each other again on a 9-yard TD pass, along with kicker Kris Brown's 25-yard field goal. In the third quarter, the Panthers continued to struggle as Texans RB Ahman Green got a 13-yard TD run, while Carolina FB Nick Goings fumbled during a kickoff return. The ball would roll into the endzone, where Houston WR Kevin Walter would land on it for a touchdown. In the fourth quarter, the Texans would put the game well out of reach with Brown's 33-yard field goal. The Panthers tried to get a comeback with Delhomme and Smith hooking up with each other on an amazing 74-yard TD pass, but the deficit was too much to overcome.

Answer this question based on the article: How many touchdowns were scored in the 1st half?
4