Mikel Obi and Oscar scored second-half goals for Chelsea 2-0 victory over Derby

 John Mikel Obi and Oscar scored second-half goals for Chelsea to set up an FA Cup fourth round tie at home to Stoke and knock a resurgent Championship side Derby out of the competition.

Mikel headed in the opener from Willian's cross before Oscar sealed a comfortable win with a bending shot.

Ramires then hit the bar while Chris Martin's late strike was the only Derby shot to test goalkeeper Mark Schwarzer.

The Brazilian was booked for a second-half dive in the penalty area.