Kudla falls to Federer; milestone also eludes Kenin

   American qualifiers Denis Kudla and Sofia Kenin, who have starred in Northern California Challengers, lost today on grass in bids for their first finals in tennis' major leagues.
   Top-seeded Roger Federer beat Kudla 7-6 (1), 7-5 in the semifinals of the Gerry Weber Open in Halle, Germany.
   Kudla, 25, had not faced a seed as he reached his second semifinal on the ATP World Tour. He also advanced to the Tiburon final in 2015 and the semis in Tiburon in 2013 and Sacramento in 2015.
   Federer, seeking his 10th Halle singles title, extended his grass-court winning streak to 20 matches. He slugged 12 aces, won 84 percent of the points on his first serve (42 of 50) and saved six of seven break points against him.
   Unseeded Tatjana Maria, a 30-year-old Germany living in Palm Beach, Fla., outlasted Kenin, who won titles in Sacramento in 2016 and Stockton last summer, 6-2, 2-6, 6-4 in the semis of the Mallorca (Spain) Open.
   Maria slugged nine aces, won 81 percent of the points on her first serve (34 of 42) and converted five of seven break-point opportunities.
   Kenin, 19, appeared in her first semifinal on the WTA tour. She had ousted Caroline Garcia, seeded first and ranked sixth, in the quarterfinals for her first victory over a top-10 player.
   Kudla and Kenin were born in Ukraine and Russia, respectively, and moved to the United States as infants.