© Getty Images
The striker saw a header cleared off the line moments later before striking the bar with a rasping free kick in the 20th minute, as the World Cup winner did everything but score in the opening exchanges.
The home side did eventually move a goal head after 25 minutes when Kurt Zouma reacted quickly to pounce on a loose ball at a corner to lash the ball home for his first Chelsea goal.
Mohamed Salah then bent a shot just wide of the post, but against the run of play Bolton equalised.
Nathan Ake came close to restoring Chelsea's lead with a swerving 30-yard strike, but Lonergan was on hand again to push the effort behind for a corner to keep Bolton level.
Lonergan continued his heroics after the break as he tipped Oscar's header over the bar, but he should have done more to prevent the Brazilian's goal just a minute later.
The midfielder picked the ball up and drove at goal as Chelsea counter-attacked and sent a low shot into the corner which slipped through the grasp of Lonergan.
Loic Remy saw his first shot of the evening saved either side of efforts from Oscar and Schurrle, which flew just wide of the frame of the goal.
Schurrle had time to strike the woodwork once more as the winger continued to torment to visitors, who couldn't find a late leveller, despite a late deflected effort from Joe Mason spinning inches wide of the post.