DALLAS (AP) — Wesley Matthews has taken greater responsibility with Dirk Nowitzki out of the Dallas Mavericks' lineup much of this season. Matthews scored 20 of his 26 points in the second half of Dallas' 107-82 victory over the Chicago Bulls on Saturday night. Matthews has accepted the expanded role as Nowitzki has been limited to five games by a strained right Achilles tendon. Barnes powered the Mavericks to a 17-point first-quarter lead with eight points. Dwight Powell (17) and rookie Dorian Finney-Smith (11) had career highs in scoring, and Deron Williams had a season-high 15 assists with only one turnover. Bulls: C Robin Lopez has a career-high 11 straight games with 10 or more points. C Andrew Bogut fouled out, but had 11 rebounds and a season-high eight points.