San Francisco @ San Diego preview

Last Meeting ( Jul 20, 2015 ) San Francisco 2, San Diego 4

San Francisco rookie Chris Heston takes the mound for the first time in nine days when the Giants visit the San Diego Padres on Tuesday in the middle contest of their three-game series. The 27-year-old went 4-1 with a 2.12 ERA in seven starts prior to the All-Star break - a span which began with a no-hitter against the New York Mets - and looks to continue the success that has helped keep San Francisco contending in the National League West and wild-card races.

“In order for a team to have a good year and get to where they want to go, you have to have a surprise or two,'' Giants manager Bruce Bochy told reporters. "And (Heston) certainly has been more than that.” Odrisamer Despaigne takes the mound for the Padres, who ran their season-high winning streak to five games with a 4-2 victory Monday while snapping San Francisco's six-game run. All-Star Joe Panik is 16-for-38 with 12 runs scored in his last nine contests for the Giants, who are 3 1/2 games behind Los Angeles in the NL West and one back of the Chicago Cubs for the final wild-card spot. San Diego's Matt Kemp is 14-for-31 with four home runs and 10 RBIs in his last eight games after belting a two-run homer Monday.

TV: 10:10 p.m. ET, CSN Bay Area (San Francisco), FSN San Diego

PITCHING MATCHUP: Giants RH Chris Heston (9-5, 3.39 ERA) vs. Padres RH Odrisamer Despaigne (3-6, 4.64)

Heston allowed one run and struck out seven in 6 2/3 innings of a 4-2 victory over Philadelphia on July 12 for his fourth consecutive quality start. The Florida native, who pitched five-plus seasons in the minor leagues before a September call-up in 2014, hasn't yielded a home run in his last nine turns. Heston gave up two runs and struck out six in seven innings of a 13-8 victory over San Diego on June 25 but permitted five runs and 11 hits in five frames of a 9-1 loss to the Padres on May 6.

Despaigne was winless in his last seven appearances (0-3) prior to the break, but his ERA rose by only .08 during that span. The 28-year-old Cuban hasn't started since July 4, when he received a no-decision after allowing one run and four hits in five innings of a 2-1 loss in St. Louis and has suffered from a lack of support as San Diego scored 13 runs in his last six starts. Despaigne is 2-0 with a 0.91 ERA in five games (four starts) against San Francisco after permitting two runs in five innings of a 3-2 victory on June 23, but he wasn't around for the decision.

WALK-OFFS

1. Padres LF Justin Upton, the All-Star who is the subject of trade rumors, didn't play Monday because of left oblique tightness and remains day-to-day.

2. Giants RHP Tim Lincecum received cortisone shots in both hips to help treat a degenerative condition, which is not considered a career-threatening injury.

3. San Diego has won seven of the last eight meetings at Petco Park.

PREDICTION: Giants 3, Padres 2