BOSTON — With Boston Red Sox slugger David Ortiz waiting in the on-deck circle and the umpires convening to review a potential game-ending call, Chicago Cubs first baseman Anthony Rizzo was appropriately nervous.

Just 47 seconds later, he breathed a big sigh of relief.

After Luis Valbuena drove in the go-ahead run with a sacrifice fly off Boston closer Koji Uehara in the ninth inning, the third baseman made a game-saving stop that Rizzo dug out of the dirt in the bottom of the ninth to end the game, leading the Cubs to a 2-1 win over the Red Sox on Tuesday night.

“You look in the dugout to see what they’re saying in there because they get the phone call if he’s safe or out,” Rizzo said of the umpires waiting on the outcome of the review. “I thought he was out. Everyone else thought he was out, so it was nerve-wracking, definitely, especially with Papi coming up.”

Ortiz never got a chance this time.

After allowing left fielder Brock Holt to reach on a two-out error, Cubs closer Hector Rondon picked up his 11th save of the season when he got second baseman Dustin Pedroia to ground out to Valbuena, who dived to his left, rose to his feet and fired a one-hopper to first that Rizzo scooped up just in time to get Pedroia.

Boston manager John Farrell came charging out of the dugout to challenge the ruling, but the umpires met for less than a minute before the call was confirmed.

“From the dugout, we couldn’t tell from the angle that Rizzo stretched to receive the ball off the dirt,” Farrell said. “Just using every available opportunity to us.”

One night after the Red Sox were nearly no-hit by Jake Arrieta, who had his bid at history broken up with two outs in the eighth inning of a 2-0 win, runs again were at a premium until Boston’s usually reliable closer entered the game in the ninth.

Uehara (3-2) yielded a leadoff single to Rizzo before shortstop Starlin Castro moved him to third with a double. Valbuena, Chicago’s third baseman, brought Rizzo home with a sacrifice fly to shallow right.

“What a great at-bat,” Chicago manager Rick Renteria said. “Just still able to put enough of the barrel on the baseball to get it deep enough to score the run.”

Edwin Jackson surrendered one run on six hits in six innings for the Cubs. The right-hander struck out three and walked four before four relievers allowed just one hit the rest of the way.

Pedro Strop (1-3) picked up the win with a perfect eighth.

Pedroia went 3-for-5 with an RBI, but the Red Sox fell to 4-12 in their last 16 games. It was the 18th time this season they have been held to one run or less.

“It gets a little frustrating at times, particularly with the number of opportunities we continue to create,” Farrell said. “And that’s the thing that we have to continue to focus on internally, is that the opportunities are there and yet at times we’re not cashing in.”

Boston’s Clay Buchholz gave up one run and five hits over 6 1/3 innings, striking out two and hitting two batters in just his second start since returning from the disabled list with a hyperextended left knee.

After allowing a single to start the game, the right-hander settled in to retire 14 of the next 15 batters, but sputtered in the sixth as the Cubs knotted it at 1-1.

Center fielder Justin Ruggiano led off the sixth with a double, moved to third on a single by second baseman Darwin Barney and scored when left fielder Chris Coghlan reached on a fielder’s choice.

Jackson held the Red Sox to two hits through four innings before Boston’s bats finally came alive with two outs in the fifth.

Center fielder Jackie Bradley Jr. doubled and was held at third on a base hit by Holt. Pedroia then lined a single off the glove of a leaping Castro, plating Bradley Jr. for a 1-0 lead.