The Mavericks remain outside the post-season places in ninth spot in the West but are only two games behind the Warriors - even after their 122-120 OT defeat.
Klay Thompson top scored for the Warriors with 27 points, ably supported by Steph Curry (23, 10 assists) and Jermaine O'Neal (20).
Curry's jumper in the dying seconds of overtime sealed the win for Golden State.
Mavericks forward Dirk Nowitzki scored a game-high 33 points and also had 11 rebounds - 10 defensive - but it would be in vain as Dallas slipped outside the top eight, just behind the Phoenix Suns, who have a game in hand.
The Brooklyn Nets guaranteed their spot in the play-offs, as their 14th consecutive home win saw them dismantle the Houston Rockets 105-96.
The Nets are fifth in the Eastern Conference, just 1.5 games behind the fourth placed Chicago Bulls, after Joe Johnson (32 points) powered them past the Rockets.
The Rockets remain fourth in the West.
Just trailing Houston are the Portland Trail Blazers, who dealt the lowly Los Angeles Lakers a 124-112 hiding.
The Trail Blazers made it four wins in a row, with Damian Lillard (34 points) and LaMarcus Aldridge (31 points, 15 rebounds) influential for the victors.
For the Lakers, non-starter Nick Young had a standout performance in a losing cause; shooting 40 points from just under 33 minutes court time.
Young went 15-from-26 from the field, netting six threes in the process.