For this achievement you need to win an online challenge and "steal" at least 500 of your opponent's bolts.
There are two rounds to an online challenge. The person who creates the challenge picks the first event and the other players chooses the second event. At the end of each round whoever has the highest score wins the bolts scored by their opponent. Once both rounds are over, if you won a total of at least 500 of the other player's bolts you'll earn this achievement.
In the example below, since you won each round you would win the opponent's bolts totaling over 500.
Round 1 - Knee Up Splash
You: 400 bolts
Opponent: 300 bolts
Round 2 - Arctic Punch
You: 450 bolts
Opponent: 250 bolts