Denmark provided the upset and Germany was typically reliable as both earned 1-0 wins Saturday at the European Championship.
The Danes held off a wasteful Netherlands in Kharkiv and highly touted Germany wore down Portugal with a late winner in Lviv as co-host Ukraine staged its opening matches.
Earlier in Poland, Russia's football federation was charged by UEFA after footage emerged of Russian fans attacking stadium stewards after their team's 4-1 victory over the Czech Republic in Wroclaw on Friday. Four security staff were treated in a hospital.
UEFA's disciplinary panel will hear the case against Russia on Wednesday. It is seeking more evidence to investigate reports of "alleged abuse" directed at Czech players.
The Netherlands, which faced its own racist taunts in training before the match, spurned a series of chances in its unexpected loss.
Star strikers Robin van Persie, top scorer in the English Premier League, and Arjen Robben were the worst offenders as the World Cup runner-up failed to convert any of its 28 attempts on goal.
Denmark, the surprise winner of Euro 1992, needed only Michael Krohn-Dehli's smart 24th-minute solo effort to make a winning start in Group B. "I'm speechless, because these three points are very important," Netherlands captain Mark van Bommel said.
Group favorites Germany labored at times against a Portugal side set up to defend despite boasting Cristiano Ronaldo in attack.
German forward Mario Gomez scored with a well-guided header in the 72nd - just as intended replacement Miroslav Klose was poised to enter the game.
Portugal struck the frame of Germany's goal late in each half. First, defender Pepe's shot struck the underside of the crossbar and bounced down on the goal line, then Nani's misdirected cross skimmed the bar.
Germany and the Netherlands resume their old rivalry in Kharkiv on Wednesday.
"I refuse to throw in the towel," Netherlands coach Bert van Marwijk said. "We must beat Germany. We have done that before."
Anti-racist experts from a fans' monitoring group had reported Russia to UEFA for fans aiming racial insults at defender Theodor Gebre Selassie, whose father is Ethiopian.
Racism was a constant theme in the buildup to Euro 2012, including when Netherlands players were targeted with monkey chants by Polish spectators at a practice session in Krakow.
Saturday's matches played in Ukraine offered a first serious test of infrastructure many doubted would be ready for its 16-match hosting share of the three-week tournament.
Ukraine fans also were highlighted by a British television program focusing on racist problems at club matches in the co-host nations.
However, Russia has first fallen foul of UEFA's pledge to combat bigotry. Monitors from the Football Against Racism in Europe (FARE) fans' network are attending each match to identify offensive banners, chants and behavior, and report to UEFA within 24 hours.
"There was some suggestion that the Czech defender went to take a corner and had a few problems," FARE executive director Piara Powar told The Associated Press.
After the match, Russian fans kicked and punched stewards, who attempted to detain a man they believed had earlier thrown a flare toward the pitch. UEFA said in a statement that "around 30 fans" attacked the stewards in a "brief and isolated incident."
Later, UEFA charged Russia with "improper conduct" of its supporters relating to "crowd disturbances, the setting off and throwing of fireworks and the display of illicit banners."
A Russian nationalist flag, which breached UEFA's zero-tolerance policy on discrimination, was also identified in Wroclaw.
No arrests were made, but Wroclaw police said they have photos of 12 people involved in the attack on the stewards, and will give images to Polish border guards and Russian authorities to help capture the men.
A Russia team spokesman, Nikolai Komarov, declined comment to the AP on details of the incidents.
"The federation has many fans. You don't have control over them all," Komarov said.
A potentially volatile clash between Russia and Poland looms in Warsaw on Tuesday, which is a Russian national holiday. Fans plan to march from the city center to the stadium.
On Sunday, European champion Spain begins the defense of its title against Italy in Gdansk, Poland.
Ireland makes its comeback after a 10-year absence from a major tournament. It plays Croatia at Poznan in the other Group C match.