Falling oil prices and lower refinery input partly undermined Chevron's first quarter results, the energy giant said on Friday, as profit beat Wall Street's expectations but revenue suffered.

Chevron posted quarterly earnings excluding items of $3.18 per share, versus $3.27 a share in the year-earlier quarter, with basic earnings per share checking in at $3.20. Revenue, however, fell to $56.82 billion from $60.71 billion a year ago, hurt by volatile crude prices and refinery troubles in California.