In his first ATP World Tour event of the year, Marcos won two matches en route to the quarterfinals at the Diema Xtra Sofia Open. He defeated lucky loser Salvatore Caruso and second seed Adrian Mannarino, before falling to qualifier Jozef Kovalik on Friday.
On Wednesday, Marcos defeated Caruso 7-6(4), 6-4 in one hour and 53 minutes, firing 10 aces, while saving four of six break points faced. On Thursday, he upset Mannarino 6-7(4), 6-3, 6-1, rallying after a slow start for the victory in one hour and 56 minutes. He launched another 10 aces and converted six of 17 break chances. Marcos edged ahead 2-1 in their three head-to-head meetings.
But in Friday's quarterfinals, it was Slovakia's Kovalik who got the better of Marcos in two tight sets. He prevailed 7-6(2), 6-4. It was Marcos' first appearance in the last eight of a tournament since September, when he advanced as far in Chengdu, China.
Moving towards a return to the Top 100 of the ATP Rankings, Marcos is projected to rise to No. 110 on Monday.