(SportsNetwork.com) - The Kansas City Royals weren't going to keep winning forever, but their recently snapped 10-game winning streak should definitely have the club feeling good about itself.

The Royals also stand a good chance of bouncing back Friday evening given they haven't lost one of James Shields' starts since the beginning of May.

Shields seeks his sixth straight winning decision as he gets the call for the opener of a three-game series with the Seattle Mariners.

Kansas City has not lost a game that Shields has started since May 2, winning each of his eight outings since. The right-hander himself is 5-0 in that span with a 3.86 earned run average, including a 6-3 decision over the Chicago White Sox on Sunday.

Shields did not have his best stuff, but still won his second straight outing as he limited the damage to three runs allowed over six innings despite yielding 10 hits and a walk.

That outing was the seventh victory on the Royals' recently halted 10-game winning streak and improved Shields to 8-3 on the year with a 3.50 ERA.

"We're hitting on all cylinders. It's really nice to see," said the 32-year- old, who is 4-4 lifetime versus Seattle with a 3.83 ERA.

Kansas City returns home a half-game ahead of Detroit for first place in the AL Central, having that edge lowered thanks to Thursday's 2-1 setback. That loss was the Royals' first since June 6 and ended the Royals' first 10-game winning streak since they claimed 14 in a row in 1994.

While the Royals have been rolling behind Shields, they haven't done much in two previous meetings with scheduled Mariners starter Hisashi Iwakuma. The right-hander has won both of his previous encounters with Kansas City, logging a total of 16 scoreless innings with 16 strikeouts.

Iwakuma beat the Royals on May 8 at home, hurling eight innings of a 1-0 decision with seven strikeouts.

The 33-year-old won for the second time in three starts on Sunday, holding Texas to a run over eight innings while scattering six hits and fanning six. Iwakuma improved to 5-3 with a 2.59 ERA on the year and comes into this outing 3-0 with a 2.49 ERA on the road.

Seattle split a four-game home-and-home series with the San Diego Padres, winning the first two as the host before dropping a pair of road games. The Mariners got six shutout innings from Erasmo Ramirez in Thursday's finale, but the bullpen couldn't hold in a 4-1 loss.

"Everything just worked today, the changeups, sliders, fastballs, curveballs," Ramirez said.

The Mariners and Royals split a four-game set in Seattle earlier in May.

06/20 11:01:03 ET