Eritrea claimed the first gold of the world championships when unheralded teenager Ghirmay Ghebreslassie stormed to a shock victory in the men's marathon on Saturday.

The opening day of the worlds in Beijing will later see sprint rivals Usain Bolt and Justin Gatlin square up in the 100m heats while Mo Farah takes a shot at 10,000m history.

World number one Novak Djokovic brushed aside Switzerland's Stan Wawrinka in straight sets to advance to the semi-finals of the ATP and WTA Cincinnati Masters Friday.

The top-seeded Serb breezed past Wawrinka with little difficulty in just over an hour, winning 6-4, 6-1 to avenge his defeat to the Swiss in the French Open final.

Steven Gerrard warned Frank Lampard to be ready for "war" as the two former Liverpool and Chelsea midfield adversaries prepared to lock horns once more for their Major League Soccer sides on Sunday.

Gerrard's Los Angeles Galaxy and Lampard's New York City FC meet in Carson on Sunday in a game being hyped as the most star-studded clash in MLS history, pitting two of the league's big-spending sides against each other.

Planned closure of airspace over Rio's Guanabara Bay during sailing competitions at next year's Olympics would "paralyze" air travel and affect more than 150,000 passengers, airlines said Friday.

Currently, airliners on domestic routes fly low in over the bay past the dramatic Sugarloaf Mountain to Santos Dumont Airport, in the heart of Rio de Janeiro.

Louis van Gaal claims unsettled Manchester United goalkeeper David De Gea will not be sold to Real Madrid before the transfer window closes.

De Gea will once again be left out of the match-day squad when United take on Newcastle at Old Trafford on Saturday because Van Gaal feels the Spaniard is still not properly focused.

A second-half strike by the excellent Blaise Matuidi gave Paris Saint-Germain a 1-0 win away to Montpellier on Friday as the French champions maintained their perfect start to the new Ligue 1 season.

Matuidi's 61st-minute goal gave PSG a win that they deserved for their dominance of possession in a match of few chances on a hot night at the Stade de la Mosson.

Mats Hummels admitted Borussia Dortmund's stunning 4-3 fightback win at Norway's Odds BK in the Europa League had started "like a bad film" after they leaked three early goals.

Dortmund left themselves with a mountain to climb at Odds' Skagerrak-Arena as the Norwegians raced into a 3-0 lead after just 22 minutes of Thursday's Europa League qualification play-off.

FIFA has met with some World Cup sponsors in a meeting they demanded after a corruption crisis rocked football's governing body.

Little detail was revealed after the closed-door session Thursday, shrouded in secrecy at FIFA headquarters and attended by Adidas, Budweiser, Coca-Cola, McDonald's and Visa.

Usain Bolt's coach believes he looks good. So if Glen Mills is happy, Bolt is happy.

And everyone else should be very worried.

Novak Djokovic smacked his racket on the court after losing serve, seemingly headed for another unexplainable loss at a tournament that has eluded him. In the end, he stopped fuming and started playing like the best.

The top-ranked Serb rallied from a 3-0 deficit in the final set to a 6-4, 2-6, 6-3 victory over David Goffin on Thursday, reaching the quarterfinals of the Western & Southern Open.