The hosts dominated the opening stages and came close when Eden Hazard dragged his shot wide.
The Blues then put together a fluid passing move that saw Ramires put through on goal. The midfielder could have squared it to the unmarked Fernando Torres but instead opted to have a go, only to see his shot saved by Adam Federici.
They eventually took the lead on 18 minutes when Frank Lampard converted from the penalty spot after Chris Gunter had fouled Hazard.
Guthrie then gave the visitors the advantage just minutes later as his free kick was fumbled by goalkeeper Petr Cech into his own net.