The answer was nearly five months ago.
Lewis pitched seven innings for his 10th victory, Luis Sardinas doubled his career total with four RBIs and Texas finished off a three-game sweep of the slumping Atlanta Braves with a 10-3 win on Sunday.
"We haven't had a lot of positive to lay our hats on, and this was a big deal for us," interim manager Tim Bogar said.
The only other series sweep for Texas this season was April 21-23 in a three-game set at Oakland. The last-place Rangers still have to win at least six of their last 13 games to avoid 100 losses.
After being swept this weekend for a 2-7 trip, the Braves were four games behind Pittsburgh for the National League's second wild card with 13 games left in the regular season. They are headed back to Atlanta for a 10-game homestand.
"It happens. In April or May, you're not too worried about it," manager Fredi Gonzalez said of the Braves' slump. "The second week of September, games are running out and you start to worry about it. It's not a real good feeling. We're putting ourselves up against a wall."
Michael Choice put the Rangers ahead to stay with an RBI triple in the second. He added a two-run double in the fifth on a play when he got hurt running the bases and left the game.
Lewis (10-13) allowed five hits and walked one. The only run on the right-hander's line was a homer by Ryan Doumit in the seventh when the Rangers already led 10-0.
Braves left-hander Mike Minor (6-11) lost his third consecutive September start, allowing five runs and eight hits while throwing 107 pitches in 4 2/3 innings.
Sardinas, the switch-hitting rookie infielder who had four RBIs in his first 35 games, drove in runs in three consecutive innings. His RBI double in the fourth made it 2-0, and then he had a run-scoring single in the Rangers' six-run outburst in the fifth. His two-run double in the sixth made it 10-0.
"It feels great to help," Sardinas said. "I've been playing good defense, but being able to help also on offense is important."
Choice rounded first base and had taken a couple of steps on his double in the fifth when he suddenly slowed and basically hopped into second base. He immediately clutched his left knee after getting to the bag.
Bogar and a trainer carried Choice off the field. The team said Choice had a strained left hamstring, and an MRI was planned for Monday.
The Rangers had their most runs since a 13-6 win at Houston on Aug. 29 and matched their season high with 18 hits. There were seven players with multiple hits, led by Sardinas, Leonys Martin and Robinson Chirinos with three apiece.
Rangers 3B Adrian Beltre spent some time in foul territory, making two nice plays on foul pops.
In the fifth inning, Beltre ran to the waist-high wall beyond the dugout and leaned into the first row of seats to make a backhanded catch as two men wearing Braves shirts reached for the ball -- which deflected off the fingertips of one of them. Gonzalez came out and briefly conferred with third-base umpire Bill Miller, but there wasn't a replay challenge.
In the second, Beltre made a lunging underhand scoop on Doumit's popup along the screen fronting the Braves' dugout.
Braves: Dallas-born C Evan Gattis missed his sixth consecutive game since being diagnosed with strep throat.
Rangers: Rookie OF Jake Smolinski, who hit .389 in his first 11 major league games before a fracture in his left foot, could play for the first time since July 21 on the upcoming road trip. He felt good after running bases before the game. ... RHP Miles Mikolas (shoulder soreness) didn't feel good after playing catch and likely won't pitch again this season.
Braves: RHP Ervin Santana goes for his 15th win Monday when Atlanta begins its homestand with the first of three against NL East-leading Washington.
Rangers: After their last scheduled day off of the season, the Rangers begin their final road trip -- three games at AL wild-card contender Oakland starting Tuesday, and then a three-game set at the AL West-leading Los Angeles Angels.