SAN JOSE, Calif. (AP) -- Reigning NCAA champion Steve Johnson lost his first-round match at the SAP Open on Tuesday to Steve Darcis of Belgium, 7-6 (4), 7-6 (5).

Johnson, who lost his three previous ATP Tour matches, battled hard against the more experienced Darcis but fell just short in both tiebreakers.

Johnson won the NCAA title last year at Southern California and is looking to lead the Trojans to their fourth straight team title in his senior season. He has won 43 straight college matches.

The first full day of action featured a heavy dose of Americans with eight scheduled to play their first matches of the tournament. Only one of the five Americans who played in the afternoon session advanced to the second round as Denis Kudla beat countryman Jack Sock.

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