[UEFA CHAMPIONS LEAGUE] It was a rough night for home teams on the first day of play in the group stage of the 2009-10 UEFA Champions League. Only two teams won at home, putting several big clubs in early pressure. Here's four things we learned on Tuesday ...

Real Madrid will score plenty of goals, but preventing them will be the question mark.

In their first European test, Real's new Galacticos were cruising, 3-0, at Zurich when they gave up a pair of goals to Xavier Margairaz and Silvan Aegerter in two minutes and saw their lead reduced to one goal. Last-minute goals from Cristiano Ronaldo (his second of the game on a free kick) and Guti ended the fright, but the question remains. Will new signings, Raul Albiol and Alvaro Arbeloa, stabilize the defense? And will Frenchman Lass Diarra be the answer as the holding midfielder?

AC Milan can still count on its veterans Pippo Inzaghi and Clarence Seedorf.

With only four points in three Serie A games, Milan has lots of problems, but it can still count on its 33-year-olds Filippo Inzaghi and Clarence Seedorf. The Dutchman found Inzaghi for the first goal with a deft chip and fed Super Pippo for the second to give the Rossoneri a rather fortunate 2-1 win over Marseille.

Juventus will struggle without Diego.

Juventus' signing of Brazilian playmaker Diego from Germany's Werder Bremen was one of the most important moves of the Serie A summer. He showed his worth, setting up the winning goal in Juve's opening game and scoring twice himself in its second game. But he suffered a thigh injury on Saturday against Lazio and missed the Champions League opener against Bordeaux. Without Diego, Juve had to settle for a 1-1 tie.

Wolfsburg's burly Brazilian, Grafite, is the real deal.

At the age of 30, Grafite finally made his Champions League debut -- and what a debut it was. The Brazilian had a hat trick -- one goal with his right foot, another with his left and the third on a penalty kick -- and led German champions Wolfsburg to a 3-1 win over CSKA Moscow.