Reigning champion Jannik Sinner is through to the Sofia Open final following a straight-sets victory over Filip Krajinovic on Saturday.

The top seed is targeting his third ATP title of the season, having already triumphed in Melbourne and Washington.

And the Italian is yet to drop a set in the Bulgarian capital as he boosted his bid to reach next month’s ATP Finals with a 6-3 7-5 success.

Breaks were exchanged in the opening set before Sinner edged his nose in front, while he recovered from 5-2 down in the second by reeling off five successive games to prevail.

"It was a very tough match against [Krajinovic]," Sinner said. "We practise at times together, so we know each other's games a little.

"There was a chance to go to a tie-break, which I luckily avoided. I am happy to be in the final here again."

His opponent in the final will be second seed Gael Monfils, who also advanced in straight sets after defeating Marcos Giron 7-5 6-0.

Though 4-2 down in the opening set, the world number 20 won 11 of the next 12 games against the American, who was appearing in his first tour-level semi-final having defeated Alex de Minaur along the way.

The Frenchman's progression means he has now reached at least one ATP final in each of the last 17 years; a tally only eclipsed by Rafael Nadal (18).

"I am very happy as I was very solid - it was a very physical match with lots of long rallies," said Monfils, who also reached the semi-finals in Metz last week.

"I felt in his rhythm he was crushing the ball, so I wanted to change the speed a little and come to the net a little and step in. I think that was key for me."