OAKLAND, Calif. — Until the coronavirus took hold in the United States, Google’s parent company, Alphabet, was marching forward to another predictably strong quarter.

Calling it a “tale of two quarters,” Sundar Pichai, Alphabet’s chief executive, said on Tuesday that the company had been doing well in January and February until a “significant and sudden slowdown” in advertising revenue in March.

The result was a quarter that fell short of Alphabet’s usually stellar results but still exceeded Wall Street’s revenue expectations. Revenue rose 13 percent to $42.1 billion from a year earlier, and net income edged up 3 percent to $6.8 billion, Alphabet said.

On a conference call with analysts, Mr. Pichai said the company planned to be “thoughtful” about spending in the short term. He said Alphabet planned to slow hiring, while adjusting investments in areas like data centers and machine learning and curbing costs for travel and marketing.