Novak Djokovic eased to a convincing victory on his return from injury as Serbia took a 2-0 lead in their Davis Cup quarter-final against Spain, while Australia, France and Belgium are also on the brink of reaching the last four.
Djokovic withdrew from the Miami Open last month due to an elbow injury, but declared himself fit to play for his country and beat Albert Ramos-Vinolas 6-3 6-4 6-2 in Belgrade on Friday.
The world number two was just too good for Ramos-Vinolas, who has not taken a set off Djokovic in three matches and made 37 unforced errors as he was broken four times to suffer another loss.
Twelve-time grand slam champion Djokovic took an hour and 55 minutes to wrap up the victory in an encouraging display ahead of the clay-court season.
Serbia, champions in 2010, are on the verge of advancing to the semi-finals after Viktor Troicki saw off Pablo Carreno Busta 6-3 6-4 6-3 in the second rubber.
Australia are also firmly on course to advance from their tie with United States courtesy of wins from Jordan Thompson and Nick Kyrgios in Brisbane.
Thompson was a surprise 6-3 3-6 7-6 (7-4) 6-4 victor over Jack Sock, who later complained of having a head cold, while the impressive Kyrgios defeated John Isner 7-5 7-6 (7-5) 7-6 (7-5) at Pat Rafter Arena.
France's Lucas Pouille and Jeremy Chardy saw off Kyle Edmund and Dan Evans respectively in straight sets to leave Great Britain facing defeat in Rouen.
Belgium also need just one more rubber to make it through following a victory for Steve Darcis over Paolo Lorenzi and David Goffin's success over Andreas Seppi in Charleroi.