In late April, Apple (NASDAQ:AAPL) blew past expectations. The big numbers rode on the success of better than expected iPhone sales, the company's largest and most profitable business segment. Headed into the report, analysts expected Apple to report iPhone sales of about 38 million. Instead, Apple said unit sales were 43.7 million units, up 17% from the year-ago quarter, and beating analyst estimates for iPhone sales by about 15%. The surprise sent the stock soaring.

iPhone 5s.

While the consensus estimate for Apple iPhone sales was 38 million, one analyst in particular had a much more accurate prediction of 40.6 million. Even more interesting, her estimates have consistently been more accurate that most other analysts -- especially as of late. Who is this analyst? Morgan Stanley analyst Katy Huberty.

Given her recent accuracy with her AlphaWise survey, I've been looking forward to her estimate for this quarter. Now she has voiced her figure, and it's looking good. According to her survey, Apple will again outdo itself, shipping a whopping 39 million iPhones, or a massive 25% year-over-year boost to last year's figure. The predicted number again suggests big upside to the consensus analyst estimate. The consensus estimate for Q3 is for 35 million iPhones.

In the past four out of five quarters Morgan Stanley's survey has outperformed the consensus analyst estimate. And the AlphaWise survey hasn't been only marginally more accurate. Her survey has predicted results with 380 basis points of greater accuracy, on average.

The impact on Apple's results?
Thirty nine million iPhones would have huge implications for Apple. An outperformance in iPhone sales of 11.4% over the consensus estimate could help earnings per share significantly outperform the consensus, too. And with iPhones accounting for 57% of sales in Q2, outperformance in Apple's largest business segment will carry over to EPS. And its impact on EPS is leveraged because the company is believed to have iPhone gross profit margins as much as 1,000 basis points higher than its corporate average.

iPhone 5s. Apple showed off the iPhone 5s shooting a Burberry fashion show. The former Burberry CEO is now heading up Apple's retail business. Investors are hoping she can reinvigorate growth in the important business. Image source: Apple.

The resulting impact could be a year-over-year boost in EPS as much as 15% to 20%. If Huberty is right about Apple's iPhone sales this quarter, the consecutive duo of big year-over-year EPS gains combined with mostly bullish expectations of Apple's product pipeline readying for launch in the second half of 2014, Apple stock could still be offering investors a solid entry point.

Even after the recent run-up in the stock price, Apple trades at a discount to the S&P 500. Apple has a P/E of 15.7 and the S&P 500 trades at 18.5 times earnings. Such a conservative valuation for Apple stock could turn out to be a bargain if Apple can return to a prolonged period of double-digit EPS growth.