Austrian Dominic Thiem returned to Court 18 to finish off Greek teenager Stefanos Tsitsipas and reach the French Open third round for the third consecutive year on Thursday.
The seventh seed was leading 6-2 2-6 6-4 2-2 when the battle of the single-handed backhands was suspended because of bad light the previous day.
Thiem made sure he was not further delayed as he polished off the fourth set 6-4.
Tsitsipas, 19, had beaten Thiem in Barcelona in the build-up to Roland Garros and was bidding to become the first Greek man to reach the third round of a Grand Slam since 1969.
Thiem, beaten by Rafael Nadal in the semi-finals last year, will face Italian Matteo Berrettini on Friday.
In other early action on Thursday, Marin Cilic beat Polish qualifier Hubert Hurkacz 6-2 6-2 6-7(3) 7-5 to book a third round spot.
The Croatian third seed breezed through the first two sets virtually unchallenged by the world number 188, who stepped up his game in the third and fourth, forcing errors from Cilic.
The 21-year-old forced and then won a third-set tiebreak, but was broken in the 11th game of the fourth set with Cilic clinching the contest on his first match point with an unreturnable serve.
Cilic, who got his best result at Roland Garros last year by reaching the quarter-finals, faces German Jan Lennard Struff or American Tennys Sandgren in the next round.