CHICAGO -- Will the humble potato chip be Jason Hammel's secret for second-half success?

The Chicago Cubs right-hander said his doctor recommended consuming more chips during the All-Star break and the payoff seemed immediate.

Whether crunchy treats were a factor or not, the results weren't in dispute on Saturday afternoon as Hammel snapped a four-game losing streak in the Cubs' 3-1 victory over the Texas Rangers.

"Doc told me, 'My prescription is potato chips,' which blew me away because I've never heard a doctor say that," said Hammel, who allowed just one run on three hits in a six-inning effort. "They've got a lot of potassium and the sea salt helps to retain water.

"So I focused on that over the break and ate a lot of chips and I think it turned out pretty well."

Anthony Rizzo helped by doubling in two runs as the Cubs won their second straight in the interleague meeting to give them the series heading into Sunday's finale at Wrigley Field.

Hammel (8-5) snapped a six-game winless streak and picked up his first victory since a 5-3 win over Arizona on June 4. Closer Hector Rondon worked a perfect ninth for his 15th save.

Hammel outdueled Rangers right-hander Yu Darvish, who was making his first start since June 8 and only his fourth big-league appearance since 2014.

Darvish (2-1) pitched well until being pulled with one out in the fifth inning and said he was pleased with the outing.

"I felt pretty good," he said. "I was throwing the ball well. It was a little different feeling from the last rehab outing, in a good way. It was just trying to find a real good feel on the pitches, the pitch itself was really good."

Chicago (55-35) has won three straight while AL West-leading Texas (54-38) has lost 11 of its last 14.

The Rangers opened a 1-0 lead in the second inning on an extended two-out play. It began with an RBI infield single by Elvis Andrus that scored Ryan Rua from second.

The sequence continued with a botched throw to first and followed to a relay to catcher Miguel Montero to unsuccessfully get Rua at the plate. A pinpoint throw to second baseman Ben Zobrist followed to record the final out.

Darvish allowed a walk and his first hit in the third and then gave up a two-out double to Rizzo into the right-field corner. Rizzo's team-leading 25th two-base hit of the season drove home Montero and Tommy La Stella for a 2-1 Cubs' lead.

"I threw that slider where I wanted it to be and I struck him out on the previous at-bat," Darvish said. "And I threw it where I wanted ... but I've got to tip my hat to him."

Texas had Mitch Moreland perched at second after a two-out double in the fourth but he was stranded after Hammel fanned Rua for his sixth strikeout of the game.

Darvish departed after Hammel walked and Bryant reached on a fielder's choice.

Facing right-handed reliever Shawn Tolleson, RIzzo grounded into a fielder's choice that caught Bryant at second but put Hammel on third. But Ben Zobrist lined to second baseman Rougned Odor to end the threat.

Darvish allowed two earned runs on two hits, walked four and struck out nine.

The Cubs added on in the sixth as Matt Szczur, pinch hitting for Hammel, singled home Jason Heyward with two outs for a 3-1 lead. The hit also chased Tolleson.

Hammel, who allowed just one earned run while walking one and striking out seven, shrugged off his past struggles.

"I'm just going a game at a time, I'm not even thinking of it," he said. "I'm just going pitching-by-pitch and trusting the routine I put together with some help and trying to come out and start on a good foot."

NOTES: There are plenty of connections between Texas and Chicago, mostly one-sided. In Friday's series opener, the Cubs used pitchers who were originally drafted by the Rangers: Kyle Hendricks (8th, 2011), Carl Edwards Jr. (48th, 2011) and Justin Grimm (5th, 2010). Further, Pedro Strop made his major league debut with the Rangers in 2010. ... Sunday's start by Rangers RHP Cole Hamels (9-2, 3.21 ERA) is his first at Wrigley Field start since July 25, 2015, when he tossed a no-hitter against the Cubs while with the Philadelphia Phillies. He will face Chicago RHP John Lackey (7-5, 3.70 ERA). ... Lackey is quite familiar with Texas with 40 previous starts, his most against any opponent and fifth-most by any active pitcher against any foe. ... The Cubs' 6-0 victory Friday gave them six shutout wins by at least six or more runs, tying a record set in 1970. They also had six in 2007. ... Cubs 1B Anthony Rizzo came into Saturday with a 10-game hitting streak, his third double-digit run in 2016. He is the first in the NL with three streaks of 10 or more while two in the AL have done it: Houston's Jose Altuve and Boston's Dustin Pedroia.