By Keith Weir

(Reuters) - Goalline technology and referees spraying the pitch to mark a line where defensive walls must stand are among the innovations at the World Cup in Brazil, illustrating how the game is subtly evolving.

Following are some of the other novelties and that fans have enjoyed over the first round of matches.

"GHOST GOALS" LAID TO REST

In use at a World Cup for the first time, goalline technology showed both its value and limitations on Sunday when Honduran goalkeeper Noel Valladares knocked a rebound from the crossbar over the line before scrambling it clear. Valladares would have got away with it at past tournaments but the cameras picked up the fact that the ball had gone in. Although the technology worked, the message was muddled by a ruling of "No goal" in relation to the initial shot from France's Karim Benzema.

Supplied by German company GoalControl, the innovation should end the rows over "ghost goals" dating back to 1966 when such an incident famously helped England to win the World Cup.

NOW YOU SEE IT...

Referees have been whipping out a canister of vanishing spray when free kicks are awarded to mark the exact spot where defenders have to stand, 10 yards or 9.15 meters away. The foam spray, which disappears within a minute, was already a feature in Major League Soccer and will be introduced in the European Champions League next season. Its popularity has been a boon for supplier, Argentine company 9.15 Fair Play. TV images of the line where players stand have also given the boot manufactures a nice dose of free publicity.

MARCELO'S MISERY

Defender Marcelo goes down in history as the first Brazilian to score an own goal at the World Cup. He inadvertently turned a Croatian shot into his own net after only 11 minutes of the opening match, to the horror of tens of millions of fans in the host nation. The dramatic error did not prove costly as Brazil came back to win 3-1.

BOSNIA JOIN THE PARTY

Bosnia, one of the nations to emerge from the bloody break-up of Yugoslavia in the 1990s, made their World Cup debut when they met Argentina in the Maracana stadium in Rio on Sunday. Substitute Vedad Ibisevic scored in the 85th minute but that was too late to prevent a 2-1 defeat after they had conceded the fastest own goal in World Cup history.

CLINT MAKES AMERICANS' DAY

Striker Clint Dempsey became the first American to score in three successive World Cups when he struck after 30 seconds against Ghana. The goal helped to give the United States a 2-1 win. Dempsey had scored against Ghana in 2006 and netted against England in 2010.