Kansas City (37-48) at Boston (51-34)

Jon Lester(notes) had already beaten cancer and won the decisive game of the World Series when he took the took the mound against the Kansas City Royals on May 19, 2008.

It wasn’t until that night, however, that Lester established himself as a dominating major league pitcher.

The left-hander will face the Royals on Friday for the first time since he no-hit them last season as he tries to make sure his Boston Red Sox don’t fall out of first place for the first time in more than a month.

After being diagnosed with lymphoma just as he was breaking into the majors, Lester beat the disease and worked his way back by the end of the 2007 season. He was the winning pitcher in Game 4 of the World Series that year against Colorado as the Red Sox completed a sweep.

The resilient Lester didn’t fully regain his strength until last season, however, and it was beginning to show in Boston’s 7-0 win over Kansas City. He struck out nine and walked two, tossing what remains the AL’s most recent no-hitter.

“We’re on the wrong part of history,” Royals manager Trey Hillman said that night.

Lester (7-6, 4.16 ERA) went on to win 16 games with a 3.21 ERA last year, and after a rocky opening to 2009 he has once again found a groove. He is 4-1 with a 1.74 ERA in his last seven starts, striking out 61 in 46 2-3 innings.

There still hasn’t been a no-hitter in the majors this season, but Lester flirted with one on June 6, when he took a perfect game into the seventh inning against Texas. He finished with a two-hitter and 11 strikeouts in Boston’s 8-1 win.

Lester threw a season-high 122 pitches against Seattle on Sunday, allowing four runs - one earned - in 6 2-3 innings. The only time he has ever thrown more pitches was in the no-hitter, when he threw 130.

“It’s nice to be able to carry my stuff throughout the game,” Lester told his team’s official Web site. “I kept us in there as long as I could. If I can keep us within striking distance like that, we’ll win a lot of ballgames.”

The Red Sox (51-34) had a four-run lead in Thursday’s series opener against Kansas City, but lost 8-6, surrendering sole possession of the AL East lead as the red-hot New York Yankees pulled even. Boston has held at least a share of first place continuously since June 9.

The team is now 3-4 to begin a 10-game homestand that initially didn’t seem threatening, starting with visits from Seattle and Oakland.

“(The Royals) just bounced back tonight and scored runs at the right time,” said Boston designated hitter David Ortiz(notes), who homered for the second straight game and hit the 300th of his career. “The Yankees are not a surprise. They are playing great.”

Starting with Lester’s gem, the Royals (37-48) were swept in their four-game series at Fenway Park last year, but they’ve already improved on that result. Alberto Callaspo(notes), who struck out against Lester for the final out, had two doubles and two RBIs Thursday, improving his average to .303.

Brian Bannister(notes) will also hope to reverse his track record in Boston. The right-hander has allowed 11 runs and four home runs in 11 1-3 innings in two starts at Fenway, losing all three of his overall starts against the Red Sox.

Bannister (6-6, 3.87) has pitched well lately. Despite a 2-3 record in his last five starts, he has a 2.57 ERA and .211 opponent batting average over that span. He beat the Chicago White Sox after allowing two runs in six innings of a 6-3 win Sunday.