NBA playoffs: Loss sends Steven Adams' OKC Thunder to brink of elimination against Houston Rockets

Steven Adams' 'double-double' was one of the only highlights for Oklahoma City Thunder, who were crushed by Houston Rockets in game five of their NBA playoff series on Sunday (NZ time).

While his teammates struggled, the Kiwi centre posted 12 points and 14 rebounds, but his side moved to the brink of elimination with a 114-80 loss. 

James Harden scored a game-high 31 points and Robert Covington made a career playoff-high six three-pointers, as the Rockets welcomed back All Star guard Russell Westbrook and went ahead 3-2 in the best-of-seven series.

Houston would advance to the Western Conference semifinals with a victory in game six on Tuesday.

Harden shot 11 of 15, including 4 of 8 on three-pointers, while adding five assists to his ledger. He had little trouble scoring on Thunder guard Luguentz Dort, who had defended Harden strongly in the previous two games.

Dort struggled offensively as well, missing 13 of 16 shots, while missing all nine from behind the arc, as Houston offered uncontested looks by design.

Westbrook made his return from a right quad strain, posting seven points, six rebounds and seven assists over 24 minutes in his first action of the series. Covington tallied 22 points on 6-of-11 three-point shooting and Eric Gordon chipped in 20 points as part of a strong two-way effort.

In the second Western Conference match-up of the day, Los Angeles Lakers have closed out their first-round series against under-manned Portland Trail Blazers with a 131-122 win in game five.

LeBron James and Anthony Davis combined for 79 points to clinch the series 4-1, and were too strong for Portland, who were without injured talisman Damian Lillard.

Davis was 14-of-18 shooting for 43 points, paired with nine rebounds, while James made 14 of 19 shots, and recorded 10 rebounds and 10 assists to increase his NBA playoffs 30-point, 'triple doubles' record to 13.

The Lakers will advance to play either the Rockets or Thunder in the second round.

In the Eastern Conference, Giannis Antetokounmpo and Khris Middleton have recorded double-doubles, as Milwaukee Bucks returned to the court and made short work of Orlando Magic 118-104 to finish off a 4-1 win in their first-round series.

Three days after walking out to protest the recent shooting of Jacob Blake, the Bucks led by as many as 21 points and coasted to a fourth straight win that vaults the top seeds into an Eastern semifinal match-up with fifth-seeded Miami Heat.

The best-of-seven series between the Bucks and Heat tips off Tuesday.

Antetokounmpo put up game-highs in points (28) and rebounds (17) in leading the Bucks to their second straight first-round series win, after they had been eliminated there in eight consecutive trips to the postseason.

Middleton chipped in with 21 points, 10 rebounds and seven assists, as Milwaukee rebounded from a shocking 122-110 loss to its eighth-seeded opponent in game one with four victories by an average of 14.5 points.

The Magic, who had a losing record (33-40) in the regular season, were led by Nikola Vucevic's 22 points and 15 rebounds.