DELRAY BEACH, Fla. (AP) Sixth-seeded Steve Johnson let a big lead slip away and lost to Benjamin Becker 5-7, 7-6 (1), 6-3 Wednesday in the second round of the Delray Beach Open, then withdrew from the doubles competition because of an injured right shoulder.

Johnson, the top-ranked American in the draw, left the grounds without appearing at a postmatch news conference.

Becker was down 4-0 in the second set before his comeback.

The 34-year-old German led the first set 5-3 until Johnson broke back and won seven straight games to take a commanding lead. But the 26-year-old Californian, who saved a match point in the third-set tiebreaker of his first-round match against Australian John Millman, suddenly began to spray balls and attempt ill-timed drop shots.

Becker won the next four games and took the tiebreaker when Johnson shanked a forehand on match point.

''Tennis is such a mental game,'' said Becker, who served for the match against Taylor Fritz in the quarterfinals at Memphis last week but faltered, losing in a third-set tiebreaker.

''You're fighting for points every week. This was a very important match for both of us. In the end, I got a little lucky,'' he said.

Becker will next meet another American, 31-year-old Rajeev Ram, who had late serving problems before topping Illya Marchenko of the Ukraine 6-2, 5-7, 6-4.

While serving for the match at 5-4 in the second set, Ram hit four double faults and later squandered two chances to force a tiebreaker, sending the match into a third set.

''I was tighter than a drum,'' said Ram, ranked No. 89th. ''That's never happened to me, four double faults in a game. But I'm really proud of the way I fought back and didn't let the emotions get the best of me.''

Eighth-seeded Frenchman Adrian Mannarino also advanced to the quarterfinals, beating qualifier Tatsuma Ito of Japan 7-6 (8-6), 6-7 (4), 6-3.

Ito, ranked No. 120th, led the third set 3-1 before Mannarino, a semifinalist at this tournament last year, reeled off five straight games, yielding just nine points along the way.

Fourth-seeded Grigor Dimitrov came back from a set and 3-1 deficits in the second and third sets to beat 23-year-old Damir Dzumhur 4-6, 6-4, 6-3 of Bosnia-Herzegovina. Dimitrov, the highest seed left in the draw, meets Mannarino in the quarterfinals.