Expectations were high going into fast-casual Mexican restaurant Chipotle's (NYSE: CMG) second-quarter earnings release. Not only was the stock up more than 70% going into the quarterly update, but the company announced in February that it had returned to growth in comparable restaurant transactions and overall comparable restaurant sales have since accelerated. After market close on Tuesday, the fast-casual chain showed that momentum continued in its second quarter. The company saw double-digit growth in revenue as comparable restaurant sales and digital sales nearly doubled. Here's a closer look at the quarter. Image source: Chipotle. Beating expectations Chipotle's second-quarter revenue increased 13.2% year over year to $1.43 billion, beating analysts' average forecast for revenue of $1.41 billion. Non-GAAP (adjusted) earnings per share for the period were $3.99, easily beating analysts' consensus estimate of $3.75. Capturing Chipotle's strong financial momentum recently, the fast-casual chain's adjusted earnings per share were up 39% year over year. Chipotle's second-quarter top-line strength was helped by 19 net new restaurant openings (20 new locations and one closed location) and a 10% increase in comparable restaurant sales. Growth in this metric was well ahead of analysts' average forecast for 8.3% comps growth. Management said 7% of this growth was driven by an increase in the number of transactions at stores open at least 13 months. The rest of Chipotle's comps growth was driven by a 3.5% boost in the average check size. Also driving revenue was a 99.1% year-over-year increase in digital sales, in line with strength seen in the metric in recent quarters. Higher sales at stores open more than 13 months helped Chipotle benefit from operational leverage, contributing to earnings growth. The company's restaurant-level operating margin expanded from 19.7% in the second quarter of 2018 to 20.9%. "These strong results were delivered despite a tougher year over year comparison and benefited from better restaurant operations, more effective marketing, and leveraging our digital make line to grow sales and expand access," said Chipotle CEO Brian Niccol in the company's second-quarter earnings release. Lifting its guidance Making the quarterly report even better, management raised its outlook for the full year. The company said it now expects 2019 full-year comparable restaurant sales to rise at a rate in the high single digits year over year. This is up from a previous forecast for revenue to rise at a rate in the mid- to high-single-digit range. Clearly, management anticipates its strong momentum in the first half of the year will continue in the second half. 10 stocks we like better than Chipotle Mexican GrillWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has quadrupled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Chipotle Mexican Grill wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of June 1, 2019 Daniel Sparks has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Chipotle Mexican Grill. The Motley Fool has a disclosure policy.Source