Top seed Becker, 35, retires from Tiburon match

Benjamin Becker, shown on Tuesday, retired with
Darian King leading 6-7 (3), 6-2, 4-2 on Thursday
in the second round of the $100,000 Tiburon Chal-
lenger. Photo by Paul Bauman

   When Benjamin Becker expressed concern about his age on Tuesday, he was prophetic.
   The top-seeded Becker, a 35-year-old German, retired from his second-round match against Darian King on Thursday in the $100,000 Wells Fargo Bank Tiburon Challenger. King, 24, of Barbados led 6-7 (3), 6-2, 4-2 at the Tiburon Peninsula Club when Becker quit because of a strained chest muscle.
   Becker, who's not related to German legend Boris Becker, reached the final of last week's $50,000 Columbus (Ohio) Challenger. He lost to Danish wild card Mikael Torpegaard, an Ohio State junior playing on his home court, in three sets.
   After beating 19-year-old American Tommy Paul in the first round in Tiburon, Becker said he didn't want to continue engaging in long rallies because of his age. He'll decide in December whether to retire or play one more year.
   King, the only non-American in the quarterfinals, will take on fifth-seeded Dennis Novikov of Milpitas, located on the other side of San Francisco Bay, today at noon (live stream).
   Novikov, a 22-year-old former UCLA standout, eliminated 31-year-old wild card Brian Baker of Nashville, Tenn., 6-4, 3-6, 6-1. Baker overcame 11 operations during his career to play in the Olympics last month in Rio de Janeiro, falling in the first round to Yuichi Sugita of Japan.
   Another Bay Area product, 21-year-old wild card Mackenzie McDonald from Piedmont, advanced with a 7-6 (3), 6-2 victory over qualifier Salvatore Caruso of Italy.
   McDonald, a Tiburon semifinalist in singles and doubles (with Deiton Baughman) last year, will meet fourth-seeded Frances Tiafoe, an 18-year-old phenom originally from the Washington, D.C., area. Tiafoe dismissed Australian left-hander John-Patrick Smith 6-3, 6-3 in 64 minutes.
   The quarterfinals in the bottom half of the draw were determined Wednesday. No. 2 seed Bjorn Fratangelo will play 18-year-old qualifier Michael Mmoh, and No. 3 seed and defending champion Tim Smyczek will face Mitchell Krueger.
   Novikov is 1-0 against King, Mmoh is 1-0 against Fratangelo, and Smyczek is 3-0 against Krueger. McDonald and Tiafoe will meet for the first time.
   Here are the singles and doubles draws and today's schedule.