As measured by one key number, Facebook CFO David Wehner made Alphabet CFO Ruth Porat look like a profligate spender in the second quarter.
Facebook's second quarter operating margin, or the percentage of revenue left after deducting expenses, was 47.2 percent.
That was far better than Alphabet's margin of 26.4 percent.
(The Alphabet figure excludes the impact of the $2.74 billion European fine that was a big drag on its profit growth for the period.)
Wehner tightened down expenses even as Facebook generated revenue growth of 45 percent, more than twice Alphabet's rate of 21 percent.
That combination of surging sales and slowing expenses helped drive Facebook's shares to a record high Thursday.
To some degree, the divergence is simply because Alphabet is five years older than Facebook, and books almost 3x as much revenue -- $26.01 billion, vs $9.32 billion for Facebook in Q2. Facebook is starting from a lower base, so doesn't have to spend as much to generate growth as Alphabet does.
But the favorable comparison is not set in stone and could even go negative for Facebook in the second half.