The social campaign was launched on Twitter as the sport brand tried to bolster support for Andy Murray among tennis fans. Before Sunday's final against Milos Raonic, which the Scot duly won, Under Armour asked users of the social network to pledge their support for what it called Andy’s Wall of WILL.
It featured thousands of messages and images from Murray fans using the hashtag #MurrayWILL to participate.
PrettyGreen, UnderArmour’s PR agency which organised the campaign, told PRWeek it used 6,000 tweets to make up the image, turning it around in 24 hours – noting time was of the essence for a timely social campaign to maximise user engagement.
The agency also said it was important to gain fans' attention ahead of the match rather than hoping to gain cut-through when the action had started.
The brand has been working with Murray since December 2014, making this the first time it has been part of his Grand Slam success.
When Murray lost to Roger Federer in the semi-finals in 2015, Under Armour projected messages of support on to the Houses of Parliament to galvanise support for "his next big challenge" – the US Open.
Under Armour, a challenger brand founded in 1996, is looking to make headway in the tough elite sports market, which has long been dominated by Nike and Adidas. The apparel brand has focused on boosting support for its athletes (including golfer Jordan Spieth and heavyweight boxer Anthony Joshua), in particular by raising engagement and brand awareness through social.