UPDATE table1 AS t1 LEFT JOIN table2 AS t2 ON (t1.t2_id = t2.id)
SET t1.some_field = t1.some_field + 1
WHERE t1.id in (1,2,3) AND t2.some_field = "SOME MATCH VALUE"
SET t1.some_field = t1.some_field + 1
WHERE t1.id in (1,2,3) AND t2.some_field = "SOME MATCH VALUE"