SCOTTSDALE, Ariz. -- Tyler Viza saved his best Arizona Fall League start for last. He pitched five scoreless innings and struck out nine, tying the league high this season, as his Scottsdale Scorpions defeated the Salt River Rafters, 4-2, on Tuesday afternoon.

Viza worked at 89-91 mph with his fastball but spotted it well, so it played better than its velocity. He also kept the Rafters off balance with a changeup with cutting action and a splitter, both of which sat in the low 80s. He scattered six hits and walked just one, finding the strike zone with 53 of his 77 pitches.

• Gameday

"Pretty much every pitch was working for me today," said Viza, a 24-year-old right-hander in the Phillies' system. "In the beginning, fastballs down were kind of effective and I got them later in the game. My changeups to lefties and righties were very good. My strikeout pitch was the splitty today. Fastballs elevated too, were pretty good for me."

Viza's nine strikeouts matched Salt River right-hander Jon Duplantier (D-backs) for the most in Arizona this fall and the second-most in an AFL game in the last 10 seasons. Peoria Javelinas right-hander Kyle Zimmer (Royals) fanned 11 in five innings in a 2014 start. Duplantier, whose nine whiffs came in his previous outing, worked four shutout innings Tuesday and struck out five -- all on secondary pitches while operating at 93-95 mph with his fastball.

Scottsdale's victory kept all three teams alive in the East Division playoff race with two games remaining. Salt River lost its fifth straight contest but remains in first place at 15-13, 1 1/2 games ahead of both the Scorpions and the Mesa Solar Sox, who are 13-14-1.

A Phoenix high school product, signed as a 32nd-rounder in 2013, Viza opened the AFL with two scoreless starts totaling seven innings, then got knocked around in his next two trips to the mound before rebounding in his final two. He ended the Fall League with a 3.47 ERA and a 20/7 K/BB ratio in 23 1/3 innings.

Just as he did in the AFL, Viza also finished the regular season with a flourish. A starter throughout his pro career, he opened 2018 in the bullpen at Triple-A Lehigh Valley and got sent down to Double-A Reading at the end of April. He worked his way back into the rotation at Reading, however, and posted a 2.06 ERA with a 56/16 K/BB ratio in 65 2/3 innings over 11 starts.

"I'm very comfortable being a starter," Viza said. "It was definitely a mixup for me being in the bullpen, but I definitely enjoyed my time there and I learned a lot, how to pitch there with runners on base. Down the road, going back into the rotation, it helped me."

When Salt River shortstop Jazz Chisholm (D-backs) snapped a scoreless tie with a two-run triple in the seventh, the Rafters needed just nine more outs to clinch the East. But Scottsdale first baseman Peter Alonso (Mets) snapped a 4-for-41 slump with a two-run double to tie the game in the bottom half, and right fielder Austin Listi (Phillies) singled him in two batters later with the go-ahead run. Sam Wolff tied for the AFL with his third save after working a scoreless ninth inning.

Jim Callis is a reporter for MLB.com. Follow @jimcallisMLB on Twitter. Listen to him on the weekly Pipeline Podcast.