Paul fractures hand as Clippers lose, Thunder win Mavs series 4-1
Next up for the Oklahoma City Thunder are the San Antonio Spurs, while the Charlotte Hornets and Miami Heat are tied at 2-2.
The Los Angeles Clippers were pegged back by the Portland Trail Blazers in their first-round NBA play-off series as Chris Paul suffered a fractured hand.
Portland levelled the Western Conference play-off at 2-2 via a 98-84 victory on Monday.
And the Clippers' woes were compounded by a significant injury to Paul in Portland.
Paul, who had 16 points in 25 minutes, fractured his third metacarpal in his right hand in the third quarter and did not return.
Al-Farouq Aminu recorded 30 points and 10 rebounds for the Trail Blazers.
The Oklahoma City Thunder secured their passage through to the Western Conference semi-finals after seeing off the Dallas Mavericks 118-104.
Russell Westbrook and Kevin Durant both starred as the Thunder - set-up by a 35-point first quarter - sealed the first-round play-off series 4-1 on Monday.
After Mavs owner Mark Cuban said he was overrated, Westbrook was immense again, posting 36 points and 12 rebounds for another double-double, while he also had nine assists.
Durant scored 33 points and team-mate Steven Adams contributed 15 points and 10 rebounds for the Thunder, who will now face the San Antonio Spurs in the second round, starting Saturday.
The Mavs were led by Dirk Nowitzki's 24 points on the road in Oklahoma City.
In Charlotte, the Hornets defeated the Miami Heat 89-85 in game four to level the series, having opened the first-round play-off with back-to-back defeats.
Kemba Walker - who posted a play-off career-high 34 points - inspired the Hornets, scoring 11 consecutive points in the fourth quarter as they evened the Eastern Conference series at 2-2.
Courtney Lee sealed the home win with a pair of free throws 4.6 seconds from the end, while Jeremy Lin added 21 points.
Joe Johnson had 16 points for the Heat, who will host game five in Miami on Wednesday.