Elon Musk has overtaken Amazon . com Inc. founder Jeff Bezos as the world’s richest person, driven by a meteoric rise in the value of Tesla Inc., the electric-car maker he runs.

The bragging rights around personal wealth pit two of the tech industry’s biggest rivals in a competition that spans from the roads to outer space. Messrs. Musk and Bezos, both founders of rocket companies, have clashed over issues such as Amazon’s power over book publishing and Mr. Musk’s interest in colonizing the planet Mars. Amazon last year bought a self-driving-car startup that would compete with Tesla.

Mr. Musk’s net worth totaled around $181 billion as of market close Wednesday, up from roughly $30 billion a year ago and about $3 billion shy of Mr. Bezos’s wealth, according to the Bloomberg Billionaires Index. The value of Tesla’s shares rose almost 8% Thursday, enough for Mr. Musk to overtake Mr. Bezos in the wealth ranking. Amazon’s stock was up less than 1%. Mr. Bezos held the top spot for more than three years. Mr. Musk’s net worth rose to $188.5 billion as of 10:15 a.m., topping Mr. Bezos’s by $1.5 billion, according to Bloomberg.