The High Desert first baseman went 4-for-4 with two homers and seven RBIs in the Mavericks' 17-11 loss to visiting Inland Empire. He has 18 homers on the season and leads the California League with 80 RBIs.
Poythress got the Mavs on the board early with a sacrifice fly in the bottom of the first inning, but Inland Empire answered with 16 runs in the next four innings.
A second-round pick out of the University of Georgia in 2009, Poythress singled in the third and fifth before slugging his first homer of the night, a three-run shot to straightaway center, in High Desert's five-run sixth inning.
He delivered another three-run blast -- this time to left field -- in the eighth, cutting the 66ers' lead to 17-11.
Poythress' huge game wasn't enough to overcome the barrage of hits coming off Inland Empire's bats however. The visitors hit four home runs among their 20 base hits in the game. Center fielder Ramon Jean, who homered, doubled twice and drove in five runs, was one of six 66ers with multiple hits. Scott Van Slyke fell a triple shy of the cycle, going 3-for-6 with three RBIs.
High Desert leadoff man Kyle Seager went 3-for-4, extending his hitting streak to 26 games and shortstop Edilio Colina collected four singles in the game. Johermyn Chavez hit a solo home run, his 23rd of the season, in the fifth.
Inland Empire starter Nathan Eovaldi (3-5) earned the win despite yielding three runs on 10 hits in five innings. He struck out three and walked a pair.
The Mavericks' Cheyne Hann (1-5) -- making the first start of his pro career after 90 relief appearances -- took the loss. He gave up seven runs on eight hits while fanning two in 2 2/3 innings.