It took the visiting league leaders a little while to get going, but when they did, a couple of chances arrived.
They eventually broke the deadlock with 23 minutes on the clock. Cesar parried clear a low shot from Robin van Persie, but Rafael was on hand to fire the rebound into the top corner of the net from 25 yards out.
Rafael then played a role at the other end of the pitch with 34 minutes played as he cleared a header from Christopher Samba off the line. From the resultant counter-attack, Van Persie was close to putting United 2-0 up, but Cesar managed to save his volleyed effort.
That was to be Van Persie's last major involvement as he was forced to limp off just before the break with a back injury that he suffered during the build-up to Rafael's goal.
As the half drew to a close United captain Nemanja Vidic had a headed chance from close range, but he failed to hit the target.