BOSTON -- Jon Lester allowed no earned runs for the third time in four starts, and the Boston Red Sox completed a three-game sweep of the Kansas City Royals with a 6-0 win Sunday.
In eight innings, the All-Star left-hander struck out eight and gave up two walks and four hits. Only one Royals player reached third base.
Lester (10-7) is 4-0 with a 0.85 ERA over his last seven starts with 47 strikeouts and eight walks in a span of 52 2-3 innings. He has yielded just one earned run in 31 innings.
Lester extended his scoreless streak to 14 innings before Junichi Tazawa got the first out of the ninth. Edward Mujica retired the next two batters.
Yordano Ventura (7-8) gave up all six runs.
The first scored on Dustin Pedroia’s forceout at second base in the first, Daniel Nava hit a two-run double in the third, and Boston added three in the fourth on David Ross’ two-run homer and Nava’s sacrifice fly.
That was more than enough support for Lester as he keeps building a case for a lucrative contract following the one that expires after this season.
Boston entered the game in last place in the AL East, percentage points behind Tampa Bay, but won for the seventh time in eight games.
Kansas City went scoreless after losing 2-1 Saturday night. The Royals have lost nine of 12 and are 9-17 since a 10-game winning streak
The Royals put runners at first and second in the first when Eric Hosmer was hit by a pitch with two outs and Danny Valencia singled.
Alcides Escobar was left on base after a one-out single in the second, and Lester retired eight consecutive batters before Escobar led off the fifth with a double. He reached third on a one-out groundout, but the threat ended when Lorenzo Cain flied out, leaving him hitless in 22 at bats.
Hosmer singled with one out in the sixth to extend his hitting streak to 16 games. After Valencia struck out, Gordon drew a walk, the first issued by Lester in three starts. But Billy Butler grounded out.
Cain walked leading off the eighth, but Lester finished his outing by getting Omar Infante to ground into a double play before fanning Hosmer.
Brock Holt scored Boston’s first run after he and Nava singled. Nava’s double in the third came after a walk to Ross and a single by Jackie Bradley Jr. In the fourth, Shane Victorino doubled and scored on Ross’ sixth homer. Nava’s sacrifice fly drove in Bradley, who had singled.
SUNDAY NOTES: Boston 1B Mike Napoli had the day off after hitting the go-ahead solo homer in the sixth inning Saturday. ... SS Escobar made an error in each of the three games. ... Jeremy Guthrie (5-8) pitches for Kansas City against Chris Sale (8-1) in the opener of a three-game series at the Chicago White Sox on Monday night. John Lackey (9-4) takes the mound for Boston against Drew Hutchison (6-8) when the Red Sox start a four-game series at Toronto.
SATURDAY NOTES: Boston’s last eight home wins have all been by one run. ... The Red Sox activated RF Victorino from the 15-day DL before Saturday’s game and optioned OF/INF Mookie Betts to Pawtucket. Victorino, who had been on the DL since May 24 with a strained right hamstring, got a nice ovation before his first at-bat, and went 1 for 3. ... Actor Steve Carell of "The Office" was in the stands, wearing a Red Sox T-shirt.