HALLE, Germany, June 11 (UPI) -- Seeded players Milos Raonic and defending champion Philipp Kohlschreiber won close straight-set matches Monday at the grass-court Gerry Weber Open in Germany.
Raonic, seeded No. 5, capped opening-day play with a 7-5, 7-6 (7-1) win over Philipp Petzschner. Raonic pounded out 19 aces and lost only 11 points over 12 service games.
Still, he managed just one break opportunity, which won him the first set, as Petzschner won a healthy 71 percent of the points on serve.
The eighth-seeded Kohlschreiber, who defeated Petzschner in last year's Weber final, ousted Dustin Brown 7-6, (7-4), 7-6 (7-4). Each player managed one break in the match. Kohlschreiber dropped just 12 points in his 12 games serving.
In other matches, Lukasz Kubot topped Jarkko Nieminen 6-4, 6-4; Cedrik-Marcel Stebe edged Carlos Berlocq 6-3, 3-6, 7-5; Mikhail Youzhny raced past Robin Haase 6-3, 6-2; and Zhang Ze defeated Tobias Kamke 6-4, 7-6 (7-2).
The Weber, which No. 2-seeded Roger Federer has won five times since 2003, serves as one of the first grass-court tournaments of the season. World No. 2 Rafael Nadal, who won his seventh French Open Monday, is entered as the top seed this year.