Consumer electronics retailer Best Buy's (BBY -0.81%)  earnings report for the first quarter of fiscal year 2015 sparked a surge of investor confidence, sending the stock as much as 8.4% higher in early morning trading today.

Best Buy's revenue slipped 3.3% lower year-over-year, landing at $9.0 billion. Non-GAAP earnings still managed to increase from $0.32 to $0.33 per diluted share. Analysts were looking for earnings near $0.20 per share on $9.2 billion in sales, making it a mixed quarter.

Same-store sales slipped in both the domestic segment and key international markets such as Mexico, Canada, and China. Home theater systems and tablet computers were particularly weak in the first quarter, balanced by growth in whiteware appliances and gaming systems. At the same time, cost reductions under the "Renew Blue" banner ran ahead of schedule, driven by corporate-level reorganization and a more efficient operating model for individual Best Buy stores.

Looking ahead, Best Buy expects same-store sales to continue falling in the second and third quarters. CFO Sharon McCollam noted in the press release that the company is expecting "ongoing softness in the mobile phone category as consumers eagerly await highly-anticipated new product launches."

Best Buy CEO Hubert Joly was quoted in the press release as saying, "We achieved market share gains in the U.S., fueled by our improved price competitiveness and an enhanced customer experience focused on advice, service and convenience."