Google and Amazon are igniting a new competitive battle in the retail market and this time it's all about being the top delivery service.

Google is expanding its nearly two-year-old overnight delivery service, Google Express, to 25 million more potential customers in six states in the Midwest. Until the announcement, Google Express was providing same-day delivery in seven metro areas and overnight service in Northern California.

"One thing is especially clear: people love saving time with us. That's what we're really about. Think back-to-school shopping that gives back those last moments of summer. Or family shopping that leaves more time for the family," stated Google Express General Manager Brian Elliot in a blog announcement.

On the same day, Amazon debuted free restaurant delivery service [pictured] in Seattle, and the list of local eateries includes Cactus, Wild Ginger, Skillet, Marination Station, Re:public, Café Yumm!, Ten Mercer and Mamnoon.

The 'free' aspect is for a limited time and available to Prime members, according to a company release, through the Prime Now mobile app. Users can checkout menus, place an order and track the delivery process. Food is delivered within an hour or less of a completed order.

"Prime members can now enjoy food from the Seattle restaurants they love without having to drive all over the city," stated Gus Lopez, general manager, Amazon Restaurants, in the release. "For many of these restaurants, this is the first time they are offering delivery, and we are delighted they have chosen to work with us."

Just two weeks ago Amazon initiated one-hour delivery service for beer, wine and other liquor beverages in Seattle. As a Boston Globe report noted the two ecommerce titans are hoping to grab a big piece of a looming market pie -- online groceries are a $10.9 billion U.S. industry and growth ahead is expected to be 9.6 percent annually through 2019.

Amazon stated it will expand the list of service Seattle zip codes in the coming days. Prime members can enter a zip code to see if Prime Now is available in their area.

One participating Seattle restaurant views the service as a great opportunity to expand its customer Relevant Products/Services base.

"By offering restaurant delivery through Prime Now, we are able to reach customers who are craving our Skillet deliciousness, but don't have time to swing by," Jon Severson, Skillet president, stated in the release. "Now, with just a few taps on their phone, Seattle customers can get their favorite Skillet menu items delivered directly to their door in less than an hour."

Another participating restaurant noted Amazon's brand and high-quality service is exactly what his business looks for in a partner.

"We are excited to team up with Amazon's Prime Now service to offer customers a convenient and fast delivery option for lunch and dinner," said Scott Campbell, director of operations, Wild Ginger, in the release. "Working with Amazon allows us to align our product quality and customer service standards with a brand that our customers know and trust."