The new Real Madrid winger’s 20th-minute goal – which came despite claims of offside – meant the Irish could not celebrate the first football international at Dublin’s new Aviva Stadium, which also marked the 100th appearance by captain Robbie Keane.
Ireland coach Giovanni Trapattoni missed the match being in hospital suffering of food poisoning.
Blanc fielded eight new internationals against Norway followingFrance’s World Cup debacle, but his team lost 2-1 in Oslo despite taking the lead through halftime substitute Hatem Ben Arfa.
Forward Erik Huseklepp capitalized on two defensive errors as France’s poor run continued, having crashed out of the World Cup in the first round in June following a player revolt against then coach Raymond Domenech.
World Cup winners Spain snatched a late draw away to Mexico thanks to David Silva’s late equalizer after new Manchester United striker Javier Hernandez had scored in the 12th minute.
Runners-up the Netherlands were also held to a 1-1 draw away to Euro 2012 co-hosts Ukraine, with midfielder Jeremain Lens putting the Dutch ahead before Alexander Aliev leveled two minutes later on 74.
World Cup semifinalists Germany led Denmark 2-0 before the hosts battled back to earn a 2-2 draw in Copenhagen.
The Germans, who finished third in South Africa, went ahead through strikers Mario Gomez (19) and Patrick Helmes (73) but Danish substitute Mads Junker set up winger Dennis Rommedahl and then equalized with four minutes to play.
Uruguay, who also reached the last four, won 2-0 away to Angola thanks to goals in the last six minutes from striker EdinsonCavani and young debutant forward Abel Hernandez.
New Russia coach Dick Advocaat tasted victory in his first match in charge, beating Bulgaria 1-0 in St. Petersburg thanks to a sixth-minute winner from midfielder Roman Shirokov.
South Africa also started a new era on a winning note as coachPitsoMosimane oversaw a 1-0 victory against World Cup quarterfinalists Ghana in Johannesburg.
Striker KatlegoMphela scored the only goal three minutes before halftime, having also netted in the 2-1 win over France in South Africa’s final group match of the World Cup on June 22.
Earlier in the day, five-time world champions Brazil made a winning start under new coach Mano Menezes, beating the United States 2-0 in New Jersey.
Teenage striker Neymar scored on his senior debut and recalled AC Milan forward AlexandrePato netted the other goal as Menezes gave six players their first Brazil outings.
The friendlies were part of a large schedule of internationals held in preparation for next month’s start of qualifiers for Euro 2012 and the 2012 African Nations Cup, and January’s Asian Cup.