Two tournament favourites the Netherlands and Scotland progressed to round two of the World Cup of Darts on Friday but three of the seeds were sent packing on an eventful night in Frankfurt.
The Dutch defending champion pairing of Raymond van Barneveld and Michael van Gerwen powered past Team USA's Darin Young and Larry Butler in their round one match.
World number one Van Gerwen played with his usual dynamism, piling up the big scores and hitting clean checkouts, including an impressive 150 in the second leg.
The USA didn't make things easy for the Netherlands with Butler and Young both adding a leg with checkouts of 100 and 105 respectively. But the strength of the Dutch duo prevailed as they went on to win 5-2.
After the match Van Gerwen told Sky Sports: "It means a lot to represent your country and I'm playing really well with Raymond.
"This is just a warm up for tomorrow and I'm looking forward to playing the rest of the tournament. Last year we won it and I think we can do exactly the same this year. That's the goal and nothing else.
"We're here to one job and that's to win the tournament."
They will play South Africa in the second round on Saturday. The 14th seeds came back from two legs down to win a tight match with Finland 5-4. World number 62 Devon Peterson secured the win for South Africa hitting double 10 after both nations had missed darts at double tops for the match.
World and Premier League champion Gary Anderson got off to a flying start with Scotland teammate Peter Wright as they breezed past Singapore's Paul and Harith Lim 5-1.
The Scottish pairing, who are seeded second in the tournament, will play Hungary in the next round.
After the match when asked about their chances, Anderson told Sky Sports: "We'll just keep plodding along."
In the opening game of the night New Zealand caused an upset knocking out 11th seeds Canada. Sky Sports pundit and three-time world champion John Part couldn't prevent Rob Szabo and Warren Parry from snatching the win. Parry played some impressive darts and closed out the match in the deciding ninth leg with a classy 92 checkout.
The Hungarian pairing of Nandor Bezzeg and Gabor Takacs produced a terrific performance to knock out 15th seeds Sweden 5-2. They will play Scotland in the second round on Saturday.
There was another upset on the cards when Hong Kong knocked out the seventh seeded Wales duo of Mark Webster and Jamie Lewis. Royden Lam produced the performance of the night with cool finishing and an incredible 131 checkout.
The Republic of Ireland made sure they didn't face an embarrassing first round exit as Connie Finnan & William O'Connor put in a flawless performance to whitewash Poland.
While the sixth seeded Northern Irish duo of Mickey Mansell and Brendan Dolan stood up to a strong fight from Thailand to make it through to the second round with a 5-2 win. The pair, who reached the semi-finals of last year's tournament, will play New Zealand on Saturday.
First Round results - Friday June 12
Canada (11) 4-5 New Zealand
Sweden (15) 2-5 Hungary
Wales (7) 3-5 Hong Kong
Republic of Ireland (10) 5-0 Poland
Northern Ireland (6) 5-2 Thailand
Scotland (2) 5-1 Singapore
Netherlands (3) 5-2 United States of America
South Africa (14) 5-4 Finland