Washington 101-73 Charlotte Indiana 103-97 Detroit     New Jersey 87-105 PhiladelphiaMilwaukee 92-86 TorontoSAN ANTONIO – The San Antonio Spurs have locked up another No. 1 seed. Now comes trying not to blow it again.Tim Duncan scored 18 points in what might have been his last game before the playoffs start this weekend, now that the Spurs have clinched the top spot in the Western Conference after beating the Portland Trail Blazers 124-89 on Monday night.The Spurs won their eighth straight but won’t care about the streak or little else with two now-meaningless regular season games left. All that will matter is their Big Three reaching the postseason fully healthy for the first time since 2008, and that likely means an easy week ahead for Duncan, Tony Parker and Manu Ginobili.‘’It’s great to be in that situation, but as we showed last year, someone can sneak up and take you out easily,’’ Duncan said. ‘’Hopefully we get a much better effort this year and do a much better job this year, and we stay away from those injuries.’’After cruising to the No. 1 spot last season against all expectations, the Spurs bowed out as just the fourth top seed to lose in the first round. This latest one - their sixth top seed in the Duncan era - is somehow even more surprising. Two days before Duncan turns 36, the NBA’s standard-bearers beat out the young Oklahoma City Thunder for ultimate home-court advantage.