Throw in their 10th straight errorless game, and the AL East leaders stretched their winning streak to six games Wednesday night with a 9-3 victory over the Washington Nationals.
"It's hard to put everything together at once," said Ortiz, whose grand slam gave Boston a 4-0 lead in the second inning. "When you put it together like we are right now, it's great because that gives you a chance to win a lot of games."
Lester (2-0) made just his third major league appearance, all starts this month, and allowed one run on three hits with 10 strikeouts and two walks in six innings. He finished his night by striking out Matthew LeCroy on a 92 mph fastball. The left-hander pumped his fist before walking toward the dugout to a standing ovation.
"It's nice," he said of the fans' reaction. "Now things are starting to slow down a little bit so I can appreciate things more."
Lester, Boston's top pitching prospect when he joined the team on June 10, had the most strikeouts by a Red Sox pitcher this season -- Curt Schilling and Tim Wakefield each had nine in a game -- and the most by a Boston rookie since Casey Fossum also had 10 against Cleveland on Sept. 18, 2002.
"He made them respect all his pitches," Boston manager Terry Francona said. "The slow breaking ball, his cutter, his fastball, his four-seamer. They couldn't get a bead on one of his pitches. ... He threw them all for strikes."
Ortiz hit his 21st homer of the season and fifth career grand slam to increase his AL-leading RBI total to 64. The homer came against rookie right-hander Shawn Hill (1-2) as Boston completed a three-game sweep after sweeping a three-game series in Atlanta.
"What am I thinking?" at that point, Washington manager Frank Robinson asked. "Don't let him hit a grand slam. You've got to pitch him tough."
The Red Sox outscored the Nationals 26-9 and out-hit them 46-22 in the series. Boston scored four runs in both the second and sixth innings, all with two outs.
"It's hard to justify it when you get beat that bad every game," Nationals catcher Brian Schneider said. Lester "threw strikes. I know he gave us a lot of pitches to hit, we just didn't hit them. I don't know if he pitched that good or we were that bad."
Washington lost for the eighth time in 10 games with the only wins coming in its last at-bat last Saturday and Sunday against the New York Yankees.
With starters Matt Clement, David Wells and Lenny DiNardo on the disabled list, Lester has filled a void in the rotation after appearing in just 11 games at Triple-A before being called up from Pawtucket.
"It's nice that I've gotten the opportunity," Lester said. "Hopefully, they'll let me keep going."
He allowed his only run in the third inning on a double by Damian Jackson and an RBI single by Alfonso Soriano that was a bloop over the head of first baseman Kevin Youkilis.
The Red Sox made it 5-1 in the fifth when Trot Nixon doubled, took third on Jason Varitek's single and scored on Mike Lowell's double-play grounder.
They added four runs in the sixth after Alex Gonzalez led off with a double. He took third on Mark Loretta's grounder for the second out. Ortiz was walked intentionally and Manny Ramirez singled in Gonzalez.
Mike Stanton replaced Hill and allowed a two-run double to Nixon and an RBI double to Varitek that made it 9-1.
Washington scored a run in the seventh on Robert Fick's RBI single and added another in the ninth on Jackson's RBI single.
"The pitching wasn't very good this series and the hitting was nonexistent," Robinson said. "We had no chance."
- Ortiz is one of three players in major league history to hit all five of his grand slams in the same park. Cecil Cooper did it at County Stadium in Milwaukee and Ken Williams did it in Sportsman's Park in St. Louis.
- Boston improved to 8-1 in interleague play, winning its sixth in a row against NL teams.
- The Red Sox are 9-2 in their last 11 games at Fenway Park.
- Boston errorless streak is its longest since going 10 games from Sept. 26 to Oct. 5, 1986.
- The Nationals/Montreal Expos franchise is 0-9 at Fenway.
- Washington pitchers have allowed at least 10 hits in 10 of the last 13 games.