Reflecting on the past 18 months amid a historically challenging environment due to the COVID-19 pandemic, I am incredibly proud of Under Armour's global team and the way we've worked to hold ourselves accountable to our strategic playbook.
In Footwear, Flow Velociti performed well in all regions, as did HOVR Phantom and Machina 2, including significant growth against last year's already strong performance.
Our Charged Pursuit 2 and Assert 9 footwear offerings also posted substantial numbers, demonstrating continued success in our segmentation strategy to bring premium innovations across all price points.
In Curry, we saw success on and off court with our Curry Flow 8 signature shoe as well as retro styles that we pre-released in APAC, all good signs of momentum as we work toward the launch of the Curry 9 late this year.
And finally, the Project Rock 3 shoe, which combines UA HOVR and TriBase technologies for a highly comfortable and stable training platform, was also a standout.
Versus 2019, North American revenue was up 11% in the second quarter and about 3% for the first half of the year.
With second-quarter revenue up 25% versus 2019 or up 35% for the first half on a two-year stack, our results gives us confidence that the additional investments we're making into marketing, CRM, digital activations, and store expansions are working to drive greater brand affinity amid a highly competitive backdrop.
Second-quarter revenue was up 43% over 2019 and up 44% for the first six months on a two-year stack.
And finally, our Latin America region, where second-quarter revenue was up 17% over 2019 or is up 7% for the first six months on a two-year stack.
With a 33% increase in revenue for the second quarter and a 32% increase for the first half versus 2019, we're pleased to see the results of our multifaceted strategies come to fruition.
Ensuring that they feel valued and appreciated, we increased our minimum pay rate to $15 per hour in our U.S. business as part of a larger effort that includes professional learning and development opportunities and additional incentive plans.
In our e-commerce business, revenue was down 18% in the quarter, a result that we anticipated being the most challenging of the year considering the shift to online in 2020 following the retail lockdown.
That said, given the work we did to exit the highly promotional elements that this business experienced in 2019, along with the investments we've made in our platforms and teams over the last 18 months, and we're very encouraged by a 53% second-quarter increase versus 2019 or a 55% increase for the first six months on a two-year stack.
Throw in that we expect our eCommerce business to be up at a high single-digit rate in 2021, and that puts our growth up nearly 50% on a two-year stack.
In the second quarter, revenue was up 91% to 1.4 billion compared to the prior year.
From a channel perspective, our wholesale revenue was up 157%, driven by broad-based growth, as we lap the most significant impact from the retail door closures in the prior year.
Our direct-to-consumer business increased 52%, led by 234% growth in our owned and operated retail stores, partially offset by an 18% decline in e-commerce, which faced a difficult comp as it was the primary business driver of last year's second quarter.
Our licensing revenues were up 276%, driven by increases in our North American partner business.
By product type, Apparel revenue was up 105%, driven by strength in our train, golf, and run categories.
Footwear was up 85%, driven by our run and team sports categories.
And our accessories business was up 99%, driven by hats, bags, and sports masks.
From a regional and segment perspective, second-quarter revenue in North America was up 101%.
In EMEA, revenue was up 133%, driven by growth in wholesale and DTC, with significant strength across our wholesale and distributor partners.
Revenue in Asia Pacific was up 56%, with balanced growth across all channels.
And in Latin America, revenue was up 317%, driven primarily by lapping the store closures in the prior year.
Second-quarter gross margin came in better than expected, improving 20 basis points to 49.5%, driven by 570 basis points of pricing improvements due to lower promotional activity within our DTC channel, along with lower promotions and markdowns within our wholesale business, which was significantly impacted by the pandemic in the prior year, and 100 basis points of benefit due to changes in foreign currency.
Offsetting these improvements was a 460 basis point negative impact from channel mix, primarily driven by a lower mix of e-commerce and a larger mix of wholesale, including a higher percentage of off-price sales than last year when this channel was essentially closed for most of the quarter.
Additionally, we realized 170 basis points of negative gross margin impact related to the absence of MyFitnessPal, which will remain a headwind throughout 2021.
And finally, a 10 basis point negative impact within supply chain as our continued benefits and product costs were more than offset by higher freight and logistics costs due to developing COVID-related supply chain pressures.
SG&A expenses were up 14% to 545 million, primarily due to higher marketing costs and expenses tied to store operations, given most retail locations were closed throughout the second quarter of 2020.
Relative to our 2020 restructuring plan, we recorded 3 million of charges in the second quarter, an amount less than we had anticipated due to the timing of specific executions such as the realization of lease and contract terminations.
Throughout the plan thus far, we've realized 483 million of pre-tax restructuring and related charges.
As detailed last September, this plan contemplates total charges ranging from 550 to 600 million.
For the quarter -- for the third quarter, we expect to realize approximately 40 to 50 million in charges related to this plan.
Our second-quarter operating income was 121 million.
Excluding restructuring and impairment charges, adjusted operating income was 124 million.
After tax, we realized a net income of 59 million or $0.13 of diluted earnings per share during the quarter.
Excluding restructuring charges, loss on extinguishment of 250 million in principal amount of senior convertible notes, and the non-cash amortization of debt discount on our senior convertible notes, our adjusted net income was 110 million or $0.24 of adjusted diluted earnings per share.
Inventory at the end of the second quarter was down 26% to 881 million as we continue to drive improvements throughout our operating model, along with experiencing some inbound shipping delays due to COVID-related supply chain pressures.
Our cash and cash equivalents were 1.3 billion at the end of the quarter, and we had no borrowings under our 1.1 billion revolving credit facility.
With respect to debt, during the second quarter, we entered into exchange agreements with certain convertible bondholders for 250 million in principal amount of our outstanding convertible notes and terminated certain related capped call transactions.
We utilized net 247 million in cash, issued 11 million shares of our Class C stock, and recorded a related loss of approximately 35 million, which is captured in other income and expenses.
Post this transaction, 250 million of our convertible bonds remain outstanding.
That said, let's start at the top with revenue, which we now expect to be up at a low 20s percentage rate for the full year.
For gross margin, on a GAAP basis, we expect the full-year rate to be up 50 to 70 basis points against our 2020 adjusted gross margin of 48.6%, with benefits from pricing and benefits from changes in foreign currency being partially offset by the sale of MyFitnessPal, which carried a high gross margin rate, along with higher expected freight expenses.
With that, we now expect operating income to reach 215 to 225 million this year or 340 to 350 million on an adjusted basis.
Translated to rate, we expect to deliver an operating margin of approximately 4% or an adjusted operating margin just north of 6% in 2021.
All of this takes us to an expected diluted earnings per share of 14 to $0.16 or, excluding restructuring charges, the loss on early extinguishment of convertible senior notes and noncash amortization of debt discount on these convertible senior notes, we expect adjusted diluted earnings per share of 50 to $0.52 in 2021.
Next, we expect third-quarter gross margin to be up 130 to 150 basis points due to pricing benefits and channel mix as we anticipate lower promotional activity and lower sales to the off-price channel.
Bringing this to the bottom line, we expect third-quarter adjusted operating income to be 95 to 105 million or 13 to $0.15 of adjusted diluted earnings per share.

Summary:
In the second quarter, revenue was up 91% to 1.4 billion compared to the prior year.
For the quarter -- for the third quarter, we expect to realize approximately 40 to 50 million in charges related to this plan.
After tax, we realized a net income of 59 million or $0.13 of diluted earnings per share during the quarter.
Excluding restructuring charges, loss on extinguishment of 250 million in principal amount of senior convertible notes, and the non-cash amortization of debt discount on our senior convertible notes, our adjusted net income was 110 million or $0.24 of adjusted diluted earnings per share.
That said, let's start at the top with revenue, which we now expect to be up at a low 20s percentage rate for the full year.
All of this takes us to an expected diluted earnings per share of 14 to $0.16 or, excluding restructuring charges, the loss on early extinguishment of convertible senior notes and noncash amortization of debt discount on these convertible senior notes, we expect adjusted diluted earnings per share of 50 to $0.52 in 2021.