After losing display ad lead to Facebook, Google is back on top

After falling behind Facebook (s fb) in online display advertising revenue, Google (s goog) is back on top.

According to a new report from research firm eMarketer, the search giant is expected to earn $2.31 billion in U.S. display ad revenue, up 38.5 percent from last year. Facebook, on the other hand, will bring in $2.16 billion, up 24.4 percent from last year.

Google’s earnings will comprise 15.4 percent of the total $14.98 billion display ad market in the U.S., compared to 14.4 percent for Facebook and 9.3 percent for Yahoo. Microsoft and AOL trail with 4.5 percent and 3.6 percent respectively.

The total display ad market is expected to grow 21.5 percent, eMarketer estimates, fueled by the growth of both Google and Facebook’s ad platforms, the expansion of online ad inventory, mobile growth and additional spending on digital video advertising, particularly on YouTube.

An earlier forecast from eMarketer predicted an even larger overall market, but the research firm said it pulled back its estimate because of lower prices for display ads on ad networks and hesitation from big brands to spend big in digital display.

Google’s rise is being driven by the strength of its ad network, on YouTube and mobile display ads. According to eMarketer, Google now dominates the search, display and mobile advertising markets.

Earlier this year, eMarketer predicted that Facebook would lead Google in display advertising, but amid reports of underperformance, the research firm cut its estimates for Facebook.

Under pressure from Wall Street, Facebook will continue to push hard in advertising on all fronts, so it will be interesting to see how those numbers shift over the coming years. But by 2014, eMarketer expects Facebook and Google combined to represent 37 percent of all display ad revenue, so it’s clear that the two tech titans will continue to be the main power players when it comes to online ads.