<p>Novak Djokovic defeated Marin Cilic for the 18th time on Friday to keep Serbia alive in their Davis Cup semi-final clash with Croatia.</p>.<p>The world number one, unbeaten in singles in the tournament since 2011, triumphed 6-4, 6-2 to pull Serbia level at 1-1 in the tie.</p>.<p>It was the 20-time Grand Slam title winner's 19th successive Davis Cup win.</p>.<p>Earlier Borna Gojo, ranked a lowly 279, pulled off a surprise win over world number 33 Dusan Lajovic, 4-6, 6-3, 6-2 to give Croatia the edge.</p>.<p>The semi-final will be decided when Djokovic and Nikola Cacic tackle the world number one pairing of Nikola Mektic and Mate Pavic in the doubles.</p>.<p>Mektic and Pavic are the Wimbledon and Olympic champions.</p>.<p>Cilic, a former world number three now down at 30, carved out eight break points on the Djokovic serve but was unable to convert a single one.</p>.<p>Gojo has played well above his world ranking in the tournament so far and showed real mettle against Lajovic to come back from a set down, especially after letting slip a 4-2 and 40-0 lead in the first set, losing 17 of the next 18 points.</p>.<p>He also saw off Italy's Lorenzo Sonego (ranked 27) in the quarter-final and Australia's Alexei Popyrin (67) in the group stages.</p>.<p>"In the first set I was up 4-2 40-0, I was in control, I slipped in that game there. I got down on myself a little bit, but then the captain and the teams and the fans picked me back up," said Gojo.</p>.<p>"Obviously Davis Cup is a special competition where the pressure is bigger on everyone and I managed to play some of my best tennis here at this tournament.</p>.<p>"I'm very happy that I managed to get those big wins, ranking wise, but for me it's more important that I managed to get the point for the team."</p>.<p>Serbia have defeated their Balkan neighbours in their two previous Davis Cup meetings.</p>.<p>The first came in Split in 2010 when Serbia won 4-1 in the quarter-finals en route to winning the competition.</p>.<p>They also romped to a 5-0 thrashing in 2015.</p>.<p>Serbia, who crept through to the last eight as one of the two best runners-up, are bidding to reach a third Davis Cup final and two-time winners Croatia, who topped their group, a fourth.</p>.<p>The winners will face either Russia or Germany, who play on Saturday, in Sunday's final.</p>
<p>Novak Djokovic defeated Marin Cilic for the 18th time on Friday to keep Serbia alive in their Davis Cup semi-final clash with Croatia.</p>.<p>The world number one, unbeaten in singles in the tournament since 2011, triumphed 6-4, 6-2 to pull Serbia level at 1-1 in the tie.</p>.<p>It was the 20-time Grand Slam title winner's 19th successive Davis Cup win.</p>.<p>Earlier Borna Gojo, ranked a lowly 279, pulled off a surprise win over world number 33 Dusan Lajovic, 4-6, 6-3, 6-2 to give Croatia the edge.</p>.<p>The semi-final will be decided when Djokovic and Nikola Cacic tackle the world number one pairing of Nikola Mektic and Mate Pavic in the doubles.</p>.<p>Mektic and Pavic are the Wimbledon and Olympic champions.</p>.<p>Cilic, a former world number three now down at 30, carved out eight break points on the Djokovic serve but was unable to convert a single one.</p>.<p>Gojo has played well above his world ranking in the tournament so far and showed real mettle against Lajovic to come back from a set down, especially after letting slip a 4-2 and 40-0 lead in the first set, losing 17 of the next 18 points.</p>.<p>He also saw off Italy's Lorenzo Sonego (ranked 27) in the quarter-final and Australia's Alexei Popyrin (67) in the group stages.</p>.<p>"In the first set I was up 4-2 40-0, I was in control, I slipped in that game there. I got down on myself a little bit, but then the captain and the teams and the fans picked me back up," said Gojo.</p>.<p>"Obviously Davis Cup is a special competition where the pressure is bigger on everyone and I managed to play some of my best tennis here at this tournament.</p>.<p>"I'm very happy that I managed to get those big wins, ranking wise, but for me it's more important that I managed to get the point for the team."</p>.<p>Serbia have defeated their Balkan neighbours in their two previous Davis Cup meetings.</p>.<p>The first came in Split in 2010 when Serbia won 4-1 in the quarter-finals en route to winning the competition.</p>.<p>They also romped to a 5-0 thrashing in 2015.</p>.<p>Serbia, who crept through to the last eight as one of the two best runners-up, are bidding to reach a third Davis Cup final and two-time winners Croatia, who topped their group, a fourth.</p>.<p>The winners will face either Russia or Germany, who play on Saturday, in Sunday's final.</p>