Microsoft's Bing.com search engine surpassed Yahoo to become the number two search on Thursday, one spot behind Google.
Though preliminary results from Friday, place the search engine back in third place.
Bing captured 15.64 percent of searches in the U.S., ahead of Yahoo's 10.32 percent, according to data from StatCounter. Globally, Bing had 5.56 percent of searches, still slightly ahead of Yahoo, which was at 5.17 percent. Google still dominates the U.S. search engine market with a 71.47 percent share and 87.66 percent worldwide.
It remains to be seen if Bing falls away after the initial novelty and promotion but at first sight it looks like Microsoft is on to a winner, said Aodhan Cullen, CEO of StatCounter, in a statement.
Steve Ballmer is quoted as saying that he wanted Microsoft to become the second biggest search engine within five years. Following the breakdown in talks to acquire Yahoo at a cost of $40 billion, it looks as if he may have just achieved that with Bing much sooner and a lot cheaper than anticipated.
As of Friday morning, however, Bing and Yahoo were battling it out for search dominance in the U.S. Yahoo bested Bing with 10.75 percent of searches compared to Bing's 10.08 percent. Globally, Yahoo had a bigger lead, with 5.55 percent of searches compared to Bing's 3.73 percent.
Bing is an update to Microsoft's Live Search which includes services like Bing Travel, Cashback and Maps for Enterprise. Microsoft is estimated to be spending $80 million to $100 million on ads to help establish Bing as a viable alternative to its larger rival, Google.