The S&P 500 declined 2.4% on Friday and is down slightly on Monday, but that opens the door to buy some dividend growth stocks that fell even more than that.

The market's decline is seen as largely related to the expected interest rate increase this month by the Federal Reserve. Ultra-low rates have helped fuel this bull market, and rising rates could depress stock prices.

And this has many market participants scared. But market participants are suffering from short-term thinking

Investing guru Warren E. Buffett practices long-term investing.

How many people are selling their houses because the Fed might raise rates? Hopefully, no one.

Investors should treat their stocks the same way.

There is a buyer and a seller for every stock transaction. When people sell for the wrong reasons, investors can profit by buying in at lower prices.

Not all businesses are created equally, and investors shouldn't buy indiscreetly.

Buy high-quality dividend growth stocks at a discount, when the market opens the door.

Here are three high-quality dividend growth stocks that rank in the Top 10 using The 8 Rules of Dividend Investing. All three fell by 3% or more on Friday, and all three are high-quality businesses with 25-plus years of steady or increasing dividends that were already trading for reasonable prices before Friday's mini-panic.

One of the three is the second-largest player in North America in one of the oldest and most stable businesses in the world.

Another just underwent a significant change that has positioned it well for growth.

And the last stock is a Dividend Aristocrat, a group of 50 stocks that have paid dividends for at least 25 consecutive years.

1. Flowers Foods (FLO - Get Report)

This company, founded in 1919, is the second-largest bakery in North America, behind only Grupo Bimbo. Flowers Foods owns the following well-known bread and cake brands, among others: Dave's Killer Breads, Nature's Own, Tastykake and Wonder Bread.

The bread industry is one of the oldest industries in the world.

Amazingly, humans have been baking bread for about 30,000 years. Now that is industry stability.

Flowers Foods has rewarded shareholders with its stable cash flows. The company has paid steady or increasing dividends for 29 years.

The company's stock fell 3% on Friday and is down 30% this year due to litigation.

Flowers Foods uses 5,100 distributors to transport and stock its products. It pays these distributors as contractors, and 190 of these 5,100 distributors are suing Flowers Foods.

They claim that they were improperly classified as contractors instead of employees and were underpaid as a result. To make matters worse, the Department of Justice has opened an investigation into this practice as well.

The company's market capitalization has declined by about $2 billion during this difficult time.

FedEx went through a similar situation recently. It ended up paying out $20,000 per driver.

If Flowers Foods strikes a similar deal with its 190 disgruntled drivers, it will end up paying $3.8 million. Even if more drivers join in the Flowers' Foods lawsuit, the company's liabilities could end up being well under $10 million, a far cry from the amount by which its market cap has declined.

Make no mistake: Flowers Foods is a high-quality dividend growth stock. It has increased earnings per share at 13.4% over the past decade, and dividends have grown even faster at 16.2% a year.

The company is deeply undervalued.

2. Johnson Controls (JCI - Get Report)

Shares of this company, which is undergoing a transformation, plunged 4.5% on Friday.

The merger between Johnson Controls and Tyco International recently closed. The resulting combined company has several advantages.

First, it is based in Ireland, giving it access to lower corporate tax rates. Lower tax rates mean more money to repurchase shares, pay dividends or fund growth.

Second, Johnson Controls and Tyco International's businesses are highly complementary.

Johnson Controls was the global leader in HVAC equipment and energy storage technology. Tyco International was the global leader in fire and security.

The combined business will be able to offer a compelling mix of products and services for customers in the building construction industry.

The merger will create a whole that is greater than the sum of its parts due to the natural fit and synergies between the two companies.

But this merger isn't the Johnson Controls' only big move.

The company also plans to spin off its automotive seatings and interiors business next month. The spin-off, which will separate Johnson Controls' automotive and building businesses, makes sense in light of the recent merger. 

The spin-off will be beneficial to shareholders by better focusing Johnson Controls on what it does best and focusing the new spin-off -- to be called Adient -- on what it does best: automotive interiors.

Johnson Controls stock offers investors a 2.5% dividend yield. The company has solid growth prospects ahead due to its intelligent restructuring moves.

Growth is nothing new for Johnson Controls. The company has paid steady or increasing dividends for 38 consecutive years and has compounded dividends at 12.2% a year over the past decade.

3. W.W. Grainger (GWW - Get Report)

This is the leading company in the U.S. maintenance, repair and operations supply industry. The company has a long corporate history: It was founded in 1927 and has paid increasing dividends for 45 consecutive years.

W.W. Grainger's share price declined 3% on Friday.

Despite its long corporate history and presence in a "boring" industry, W.W. Grainger has done very well for shareholders, with EPS increasing at an annual average rate of 12.6% and dividends growing at 15.5% over the past decade.

The company has seen week results recently, however.

W.W. Grainger's adjused EPS declined 12% year-over-year in the second quarter. The company's struggles come from weakness in its customer's businesses.

Low oil prices and a struggling manufacturing sector have temporarily depressed margins for W.W. Grainger, resulting in declining earnings. The company expects adjusted EPS growth of between -6% and 2% for the full year.

Nevertheless, W.W. Grainger has historically handled recessions well. The company's earnings fell just 14% in 2009 during the worst of the recession, but they recovered to all-time highs the following year.

W.W. Grainger's management has taken full advantage of the pessimism surrounding the business. W.W. Grainger repurchased 1.8% of its shares outstanding in the past quarter alone.

The company's management is exceptionally shareholder-friendly as evidenced by its share repurchases and long history of paying rising dividends.

The stock has a dividend yield of 2.2%.

W.W. Grainger is poised to continue compounding its EPS at about 10% a year over full economic cycles. This growth, combined with the company's dividend yield, gives investors expected total returns of 12% a year over the long run.

This article is commentary by an independent contributor. At the time of publication, the author held positions in JCI and GWW.