The Kansas City Royals are atop the AL Central this late in a season for the first time in 11 years, but their stay may be brief.
Kansas City (64-53) was eight games out of first place in the Central on July 21, and erased that deficit by winning 16 of 19 games and extended its current streak by beating Oakland 3-2 in the opener of this four-game set Monday.
The Royals are one-half game ahead of second-place Detroit, which is at Pittsburgh. They haven't been atop the division this late in a season since Aug. 29, 2003.
"You want to be in first place. Our goal was to get back to first place," manager Ned Yost said. "Now our goal is to stay in first place."
Kansas City was in first place June 19 after overcoming an early seven-game deficit. The team's latest surge makes it only the third in baseball history to overcome such a deficit twice in a year, joining the 2003 Minnesota Twins and the 1916 Tigers.
Remaining in first, however, will likely require beating Lester (12-7, 2.44 ERA).
The left-hander held the Royals to three runs in 6 2-3 innings of an 8-3 victory in his A's debut Aug. 2, two days after being acquired in a major trade with Boston.
Lester followed up that win by carrying a perfect game into the sixth before finishing with a three-hitter in Thursday's 3-0 win over the Twins, looking every bit like the ace the AL West leaders sought ahead of the non-waiver trade deadline.
"You could see from the onset that he was going to be tough to score on," manager Bob Melvin said. "Not only is he able to pitch that type of game but he's also a guy that gives the bullpen a rest. That's exactly what he did."
Lester has done plenty of that over his last 10 outings, going 6-0 with a 1.21 ERA, and another meeting with the Royals could keep him rolling.
He's 8-3 with a 1.65 ERA over 12 career starts against them, but he's 1-3 with a 2.74 ERA in four games at Kauffman Stadium. He couldn't be blamed in a 5-1 loss in his most recent outing there Aug. 8, 2013, as he allowed three runs - one earned - while getting no runs of support in seven innings.
Oakland (72-46), which owns the best record in baseball, may need another gem from Lester after the offense totaled nine singles and three runs while losing back-to-back games.
Jeremy Guthrie (8-9, 4.35), who is aiming for a career-best four straight winning starts for the third time and first since July 20-Aug, 5, 2013, counters for the Royals.
He has a 3.05 ERA during his win streak after posting a 10.93 ERA losing the previous three.
The right-hander tossed a seven-hitter while retiring the final 19 batters he faced in a 6-2 win at Arizona on Thursday, six days after holding the A's to three hits in six innings of a 1-0 win.
"I think it's the pitcher's goal every time is to get as deep as they can," Guthrie said Thursday. "I haven't done that very well, especially the last couple of months. So it's nice to have a high pitch count out there early but be able to settle in and get through some quick innings."
Guthrie scattered three hits in seven innings of a 5-0 win over Oakland in his most recent matchup at Kauffman on Aug. 14, 2012.