Jerome Miron-USA TODAY Sports

Adrian Martinez threw four touchdown passes and the Birmingham Stallions remained undefeated with a 39-21 win against the host Memphis Showboats on Saturday.

The Stallions (6-0) became the first United Football League team to clinch a playoff spot and have won 13 straight games dating back to last season in the USFL. The Showboats (1-5) lost their fifth consecutive game.

Martinez completed 23 of 36 passes for 368 yards with no interceptions. Kevin Austin Jr. caught four passes for 108 yards, including an 80-yard touchdown that pushed the lead to 31-9 late in the third quarter. Marlon Williams caught two TD passes.

Memphis seized a 6-0 first-quarter lead on Case Cookus' 10-yard TD pass to Sage Surratt, but the Showboats did not find the end zone again until there was 2:29 left in the game.

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