Seattle ? Kansas City’s losing streak reached 17 games Tuesday night when the Royals lost, 4-3, to the Seattle Mariners on Yuniesky Betancourt’s go-ahead infield single in the eighth inning.

The Royals are four losses from tying the AL record of 21 in a row set by the Baltimore Orioles at the start of the 1988 season.

With the score tied at 3, Jeremy Affeldt (0-2) gave up a two-out single to Jeremy Reed in the eighth and walked Mike Morse. Reed stole third, then scored when Betancourt hit a grounder deep in the hole at shortstop. Angel Berroa fielded the ball and threw to second base, but Morse beat the play.

Joel Pineiro (5-7) won his second straight decision, pitching eight innings and giving up three runs and six hits. Eddie Guardado worked the ninth for his 29th save in 31 opportunities.

Kansas City finished with six hits, two by Matt Stairs.

The Royals’ skid started July 28 with a 10-5 loss at Tampa Bay. Four of the defeats have been by one run, including two losses in a doubleheader Sunday at Detroit.

For the second straight game, bench coach Bob Schaefer filled in for manager Buddy Bell.

Bell had been expected back from Arlington National Cemetery, where he attended services Monday for his nephew, a Marine killed in Iraq. Lance Cpl. Tim Bell Jr. was killed by a roadside bomb this month.

The teams play a day game today, with D.J. Carrasco pitching for the Royals. Then Kansas City goes to Oakland for a three-game series that begins Friday night.

The Royals grabbed a 3-2 lead in the second on David DeJesus’ sacrifice fly. The Mariners tied the score on Adrian Beltre’s sacrifice fly in the third.

In the first, the Royals went ahead 2-0 on an RBI single by Stairs and a sacrifice fly by Emil Brown. The Mariners came back to tie it in the bottom half on RBI singles by Raul Ibanez and Beltre.

Zack Greinke pitched the first six innings for Kansas City, allowing three runs and eight hits with seven strikeouts.

Notes: Ichiro Suzuki of the Mariners improved his hitting streak to 10 games with a first-inning single. Suzuki had two singles for his 46th multihit game, second-most in the AL. He also stole his 27th base. … The 21-year-old Greinke made his career-high 25th start. He has lost twice during the streak. At 3-14, he leads the AL in losses.