The second half of the 2026 ProKart Challenge began over the August 15-16 weekend at Sonoma Raceway. The Sonoma, California circuit welcomed the series for the second of back-to-back trips, hosting the fourth round of the season championship on the ‘Reverse National’ layout. Picture-perfect weather greeted the nearly 160 entries across 11 categories for the weekend.
The largest field of the season competed in Sonoma in KA100 Senior presented by Hayner Racing Team, featuring 43 drivers. Stephen Eisert used home track knowledge to grab the fast time in qualifying, earning his third top qualifier honor of the season by posting a 48.480 lap time to edge out Sebastian Hauser and two-time winner Jake Drew by 90 thousandths. Drew led most of the second half of the 12-lap Prefinal, including the final lap to score the win after Eisert was shuffled back on the final lap to outside the top five. Eighth in the race was Chase Hand, runner-up in Round Three at Sonoma. Hand quickly moved up in the 22-lap Final, reaching second by lap eight to sit behind Drew. It was Drew leading the way until the final lap when Hand was able to secure the lead, crossing the line first to claim his first victory of the season. Drew settled for second, with Flavio Aquini winning the battle for third over Archer Eversman and Round Two winner Matthew Cagle in fifth.
Pro Shifter presented by Axis Kartsport welcomed a third different winner on the season. Jesus Vasquez Jr. led the field in qualifying, recording a time of 43.195 to edge out two-time winner Billy Musgrave. Jacob Gulick got the jump on the front row starters, going from third to first over the opening lap of the Prefinal. Musgrave took back control on lap five, leading the rest of the distance over Gulick, with Vasquez in third. Musgrave was able to lead the opening three circuits of the 22-lap Final before Vasquez took over the lead. Vasquez led the remainder of the Final, going on to secure his first career victory in the category. Musgrave finished 1.7 seconds back in second, with Gulick rounding out the podium in third. Massimo Valiante retired on the final lap of the Prefinal, coming from 14th on the grid to finish fourth in the Final ahead of Oliver Hodgson.
Multiple drivers were in the mix for KA100 Junior presented by Nash Motorsportz. Braydon Wagner finished third at Sonoma in Round Three and began Round Four with quick time in qualifying with a lap of 49.512. Sixth in the session was Mateo Calderon, who won Round Three. Calderon drove up to the lead by lap three of the Prefinal, leading the rest of the distance for the win over Daniel Ramirez and Wagner. The 22-lap Final was paced by Calderon for the first 21 circuits. On the final circuit, Ramirez found a way past to secure a first career victory in the category. Calderon settled for second with Wagner rounding out the podium. Diesel Biezonsky was fourth with Cason Hodge in fifth.
It was two straight wins in Sonoma for Ryan Casner in KA100 Master presented by Precision Karting. After sweeping Round Three, Casner began the weekend second in qualifying behind Denis Dumanov, who set a time of 50.190. Casner led the second half of the Prefinal for the race win as Dumanov retired early. The 22-lap Final was all Casner, going wire-to-wire for a second victory on the season. Joshua Daley ran second with Tony Gomez holding third. Blake Lawrence and Jeffery Bays made up the top five.
One of four sweeps on the weekend came in the FZ125 Senior division presented by P1 Engines Inc. Round One winner Theo Kekati set the pace all weekend. A lap time of 45.535 edged Mathew McCoy for the fast lap in qualifying. Mathias Coito led the early laps of the Prefinal before Kekati took control and the race win. The 22-lap Final was all Kekati, leading green to checkered for a seven-second advantage and his second victory of the season. McCoy won the battle for second over Xander Malatesta, with Mason Mitchell finishing fourth and Coito fifth. James Skyers won for a fourth straight time on the year in FZ125 Master presented by Precision Works Racing. The weekend was a sweep, setting fast time in qualifying and winning both the Prefinal and Final ahead of Jeff Krogstad and Larry Hernandez Jr.
FZ65 Mini Shifter presented by Empire Karts was the third sweep of the weekend, put in by Asher Biezonsky. The two-time race winner set fast time in qualifying of 49.229 to edge out the six-driver field. Biezonsky went on to win the Prefinal and Final, securing the victory by over two seconds. Tyler Wade and Anakin Hernandez joined him on the podium. FZ85 Junior category presented by West Coast Motorsports was nearly a sweep on the weekend as well. Diesel Biezonsky cleared the field by over four tenths in qualifying and won the Prefinal by over three seconds. After leading the first 12 laps of the 22-lap Final, Biezonsky retired. This promoted Mati Dragan to the lead and a first series victory. Three-time winner Jude Sack was second, with Merce Hernandez in third.
Making his first start of the season in Mini Swift presented by Formula Works/GFC, Aidan Go swept the action on the weekend. Go edged out Round Three winner Lucas Tarango by 22 thousandths in qualifying before leading all 10 laps in the Prefinal. The 19-lap Final began with an early battle featuring Go and Chase Riddering. After Go led the first two laps, Riddering led the next five circuits. Go returned to the point and from there was able to pace the field the rest of the distance for his first victory of the season. Benjamin Tavi won the battle for second over Riddering, with Emiliano Hernandez fourth and Cole Harris in fifth.
Micro Swift presented by Parazinho Chassis Jig welcomed a first-time winner of the season in Sonoma. Two-time winner Carson Bishop set the pace over the start of the weekend, posting a fast time in qualifying to edge out Braxton Shiflett before leading all 10 laps of the Prefinal. Bishop slipped down to fourth over the opening lap of the Final, with Shiflett taking the lead. Round Two winner Benjamin Monroy jumped up to the lead, as he and Shiflett swapped positions over the next 18 laps. Shiflett secured the spot prior to the white flag and held on to the checkered flag for his first career victory. Monroy ended up second, with Dan Duculescu winning the battle for third over Bishop and Ezra Medina.
Kevin Woods was able to record a second straight victory in Master Shifter presented by Leading Edge Motorsports. Woods’ time of 44.328 was a mere three thousandths quicker than Patrick O’Neill in qualifying, but it was O’Neill getting the edge in the Prefinal over Woods. Then, the Final went the other way. O’Neill led the first five laps before Woods took over, driving away to over a four-second advantage ahead of O’Neill. Marcin Kloda joined them on the podium in third, with Ezekiel Corson fourth and Michael Faker fifth.
The second half stretch of the 2026 ProKart Challenge season will feature three different facilities. Round Five is slated for September 12-13 at the Spring Mountain Karting Complex in Pahrump, Nevada. For more information on anything related to Superkarts! USA, please visit the website – www.superkartsusa.com and be sure to follow the Superkarts! USA Facebook page, Twitter and Instagram accounts.