Competing as the top-10 player for the first time, an in-form Russian Andrey Rublev made a winning start in front of the home crowd in St. Petersburg. Andrey became the second player of the season with 30 ATP wins after Novak Djokovic, beating Vasek Pospisil 6-2, 6-4 in an hour and 18 minutes, scoring the second victory over the Canadian in three matches.
Rublev lost 18 points in nine service games, fending off three out of four break chances and creating 13 opportunities on the return, converting four to march over the finish line and advance into the second round. Vasek had a 40-0 lead in the third game, squandering four game points overall and suffering a break when his backhand landed long.
Rublev confirmed the break with a forehand winner and forced an error from Pospisil to grab another one and move 4-1 in front. Rublev saved two break chances in the sixth game to open a 5-1 gap, squandering three set points on the return in the next one and sealing the opener with a service winner at 5-2.
They traded breaks in games three and four and Andrey grabbed another one at 3-3 with a backhand crosscourt winner, sealing the deal with four winners at 5-4 to advance into the last 16. The 7th seed Borna Coric took down Feliciano Lopez 6-3, 7-6 in an hour and 36 minutes, serving at 74% and dropping only nine points behind the initial shot.
Lopez couldn't follow that pace in the opener, suffering breaks in games seven and nine before raising the level in set number two. The Spaniard saved two break chances in the second game, reaching the tie break that Coric claimed 7-2 with a double mini-break.
The 4th seed Karen Khachanov defeated James Duckworth 6-4, 6-4 in an hour and 17 minutes, losing serve once and delivering three breaks to move over the top and grab the 18th victory of the season. Karen caught a break in the first game, defending a break chance at 5-4 to close the opener.
They broke each other in games three and four in set number two before Karen secured 12 of the last 14 points from 3-4 to march over the finish line. The 6th seed Milos Raonic toppled a qualifier J.J Wolf 7-6, 6-1 in an hour and 40 minutes.
Raonic blasted 21 aces and fended off all five break points to keep the pressure on the other side of the net, unable to break Wolf's resistance in the opener before sprinting over the finish line. The Canadian had to dig deep at 4-5 in the first set, facing those five break/set points and repelling them all to extend the set and reach the tie break that he won 7-5 to gain momentum.
Wolf had nothing more left in the tank, dropping 20 of the final 24 points to push Milos over the top.