The No. 5 seed in this tournament, Sandgren didn't get as close to victory in this one, as Johnson controlled the decisive tiebreaker. Johnson had fallen to Federer in the first round at the Australian Open and earned his first ATP Tour win of the season on Monday.
In another all-American matchup, Jack Sock, once ranked as high as No. 8 but now unranked after an injury-plagued 2019, lost to Marcos Giron 6-3, 6-4 in his first singles match on tour this season. Also Monday, No. 6 seed Miomir Kecmanovic of Serbia beat American Tommy Paul 6-4, 6-2; and Italy's Andreas Seppi outlasted Damir Dzumhur of Bosnia-Herzegovina 6-3, 1-6, 7-6 (6).
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